35C - EvoScan
GROUP 35C
ACTIVE STABILITY
CONTROL SYSTEM
(ASC)
CONTENTS
GENARAL . . . . . . . . . . . . . . . . . . . . .
35C-2
ON-VEHICLE SERVICE . . . . . . . . . . . 35C-116
SERVICE SPECIFICATIONS. . . . . . .
35C-2
MEASURES FOR DISCHARGED
BATTERY . . . . . . . . . . . . . . . . . . . . . . . . . . 35C-119
SPECIAL TOOL . . . . . . . . . . . . . . . . .
35C-3
STEERING WHEEL SENSOR
NEUTRAL POINT LEARNING . . . . . . . . . . 35C-119
TROUBLESHOOTING . . . . . . . . . . . .
35C-4
HYDRAULIC UNIT (HU) CHECK . . . . . . . . 35C-116
ASC OFF SWITCH . . . . . . . . . . . . . . . 35C-120
STANDARD FLOW OF DIAGNOSTIC
TROUBLESHOOTING . . . . . . . . . . . . . . . .
35C-4
REMOVAL AND INSTALLATION . . . . . . . . 35C-120
PRECAUTIONS FOR DIAGNOSIS. . . . . . .
35C-4
INSPECTION. . . . . . . . . . . . . . . . . . . . . . . . 35C-120
INSPECTION OF ASC INDICATOR LAMP,
ASC OFF INDICATOR LAMP,
ABS WARNING LAMP AND
BRAKE WARNING LAMP. . . . . . . . . . . . . .
35C-5
DIAGNOSTIC FUNCTION . . . . . . . . . . . . .
35C-5
DIAGNOSIS CODE CHART . . . . . . . . . . . .
35C-6
DIAGNOSTIC TROUBLE CODE
PROCEDURES. . . . . . . . . . . . . . . . . . . . . .
35C-8
TROUBLE SYMPTOM CHART. . . . . . . . . .
35C-85
SYMPTOM PROCEDURES . . . . . . . . . . . .
35C-85
HYDRAULIC UNIT . . . . . . . . . . . . . . . 35C-121
DATA LIST REFERENCE TABLE . . . . . . . 35C-109
ACTUATOR TEST TABLE . . . . . . . . . . . . . 35C-112
CHECK AT ECU TERMINALS . . . . . . . . . . 35C-113
REMOVAL AND INSTALLATION . . . . . . . . 35C-121
WHEEL SPEED SENSOR . . . . . . . . . 35C-123
REMOVAL AND INSTALLATION . . . . . . . . 35C-123
INSPECTION. . . . . . . . . . . . . . . . . . . . . . . . 35C-123
G AND YAW LATE SENSOR . . . . . . . 35C-124
REMOVAL AND INSTALLATION . . . . . . . . 35C-124
STEERING WHEEL SENSOR . . . . . . 35C-125
REMOVAL AND INSTALLATION . . . . . . . . 35C-125
Main
Index
Group
TOC
35C-2
ACTIVE STABILITY CONTROL SYSTEM (ASC)
GENERAL
GENERAL
M1357000100028
Due to the adoption of the active stability control system (ASC), the service procedure has been added.
<M/T-vehicles>
Main
Index
Group
TOC
SERVICE SPECIFICATIONS
M1357003000019
Item
Standard value
Wheel speed sensor current mA
5.9 − 8.4
Wheel speed sensor insulation resistance MΩ
5 − 100
35C-3
ACTIVE STABILITY CONTROL SYSTEM (ASC)
SPECIAL TOOL
SPECIAL TOOL
M1357000200014
Tool
a
MB991824
b
Number
Name
Use
MB991955
a. MB991824
b. MB991827
c. MB991910
d. MB991911
e. MB991825
f. MB991826
M.U.T.-III sub-assembly
a. Vehicle
communication
interface (V.C.I.)
b. M.U.T.-III USB cable
c. M.U.T.-III main
harness A (for vehicles
with CAN
communication)
d. M.U.T.-III main
harness B (for vehicles
without CAN
communication)
e. Measuring adapter
harness
f. M.U.T.-III trigger
harness
ASC check (DTCs
display, service data
display and calibration by
M.U.T.-III)
MB991984
ABS check harness
Voltage inspection at
ASC-ECU terminals
MB991709
Wiring harness set
Output voltage inspection
at G and yaw rate sensor
MB991827
c
MB991910
d
CAUTION
For vehicles with CAN
communication, use the
M.U.T.-III main harness
A to send the simulated
vehicle speed. If you
connect the M.U.T.-III
main harness B instead,
the CAN
communication does
not function correctly.
DO NOT USE
MB991911
e
MB991825
f
MB991826
MB991955
MB991984
Main
Index
Group
TOC
35C-4
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
TROUBLESHOOTING
STANDARD FLOW OF DIAGNOSTIC
TROUBLESHOOTING
M1357000400018
Refer to GROUP 00 − How to Use Troubleshooting/Inspection Service Points P.00-5.
PRECAUTIONS FOR DIAGNOSIS
M1357000500015
1. ABS/ASC controls brake pressure by the
Group
assistance of ECU. The symptoms described in
TOC
the chart below may occur during the normal
ABS/ASC operation, and they do not indicate any
sign of malfunction.
Symptoms
Description of symptoms
• When the ABS hydraulic unit operates, the operating noise is
generated from the motor. (Squeak noise)
• Noise is generated from the brake pedal together with the
vibration. (Gride noise)
• When ABS operates, the system repeats the activation and
deactivation. At this time, the noise is generated from the
chassis components. (Clonk: Suspension, Squeaky: Tyres)
These noises are generated when the
system and brake pedal operate
normally, and they do not indicate any
sign of malfunction.
• A slight shock may be felt when depressing the brake pedal
lightly during the low speed driving.
• Small clicking noise may be heard from the engine
compartment.
This noise is generated when the system
operation check (startup check
performed at the vehicle speed which is a
few km/h higher than the predetermined
vehicle speed) is performed, and it does
not indicate malfunction.
2. On the snowy or gravelled roads, a vehicle with
ABS would have longer braking distance
compared to the one without ABS. Considering
this characteristics, advise the customer to drive
the vehicle safely at lower speed and not to put
too much confidence in the ABS system when
driving on the above-mentioned roads.
Main
Index
3. The diagnosis code detection condition depends
on each diagnosis code. When the trouble
symptoms are rechecked, conditions described in
the description for the diagnosis code procedures
should be met.
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
INSPECTION OF ASC INDICATOR LAMP,
ASC OFF INDICATOR LAMP, ABS
WARNING LAMP AND BRAKE WARNING
LAMP
M1357000600012
Check that the ASC indicator lamp, ASC OFF indicator lamp, ABS warning lamp, and brake warning
lamp illuminate as follows.
NOTE: The EBD warning lamp is also used as the
brake warning lamp.
ASC indicator lamp
Brake warning
lamp
35C-5
2. The ASC indicator lamp, ASC OFF indicator lamp, Main
Index
ABS warning lamp, and brake warning lamp
*1 and then
illuminate for three seconds
extinguishes *2.
Group
3. Otherwise, check the diagnosis code.
TOC
NOTE: .
• *1: The ABS warning lamp may illuminate until the
vehicle speed reaches 10 km/h. As far as
ASC-ECU stores any diagnosis code related to
the wheel speed sensor malfunction or the motor
malfunction as past trouble, ASC-ECU continues
illuminating the ABS warning lamp until it verifies
that the malfunction for that code is resolved
(start-up check).
*2
• : The lamp does not turn OFF when the parking
brake is applied or the brake fluid level is lowered.
DIAGNOSTIC FUNCTION
M1357000700019
ABS warning lamp
ASC OFF indicator
lamp
Approx.3s
Warning lamps
and indicator
lamps
Ignition
switch
HOW TO READ DIAGNOSIS CODE
Refer to GROUP 00 − How to Use Troubleshooting/Inspection Service Points P.00-7.
ON
HOW TO ERASE DIAGNOSIS CODE
OFF
Refer to GROUP 00 − How to Use Troubleshooting/Inspection Service Points P.00-7.
START
ON
ACC,
LOCK
AC601002AB
1. When the ignition switch is turned ON, the ASC
indicator lamp, ASC OFF indicator lamp, ABS
warning lamp, and brake warning lamp illuminate.
35C-6
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
DIAGNOSIS CODE CHART
M1357000800016
Main
Index
CAUTION
During diagnosis, a diagnosis code associated with other system may be set when the ignition switch
Group
is turned on with connector(s) disconnected. On completion, confirm all systems for diagnosis
code(s). If diagnosis code(s) are set, erase them all.
TOC
Diagnosis code Item
No.
Reference page
C1200
Wheel speed sensor (FR) system (open circuit or short to earth P.35C-8
or power supply)
C1205
Wheel speed sensor (FL) system (open circuit or short to earth
or power supply)
C1210
Wheel speed sensor (RR) system (open circuit or short to
earth or power supply)
C1215
Wheel speed sensor (RL) system (open circuit or short to earth
or power supply)
C1201
Wheel speed sensor (FR) system (sensor output error)
C1206
Wheel speed sensor (FL) system (sensor output error)
C1211
Wheel speed sensor (RR) system (sensor output error)
C1216
Wheel speed sensor (RL) system (sensor output error)
C1222
Wheel speed sensor system (abnormal power supply voltage) P.35C-30
C1225
Wheel speed sensor system (sensor output error)
P.35C-35
C1226
Control solenoid valve (FR) pressure holding system
P.35C-45
C1231
Control solenoid valve (FR) decompressing system
C1236
Control solenoid valve (FL) pressure holding system
C1241
Control solenoid valve (FL) pressure reducing system
C1246
Control solenoid valve (RR) pressure holding system
C1251
Control solenoid valve (RR) pressure reducing system
C1256
Control solenoid valve (RL) pressure holding system
C1261
Control solenoid valve (RL) decompressing system
C1266
Motor system (seizure)
C1273
Motor relay stuck OFF
C1274
Motor relay stuck ON
C1276
Valve relay system
P.35C-50
C1278
Valve relay system stuck off
P.35C-53
C1279
Valve relay system stuck on
P.35C-55
C1300
Cut valve (FR/RL) <primary> system
P.35C-45
C1305
Suction valve (FR/RL) <primary> system
C1310
Cut valve (FL/RR) <secondary> system
C1315
Suction valve (FL/RR) <secondary> system
C1340
Stop lamp switch signal error
P.35C-57
C1345
Low brake fluid level
P.35C-60
C1364
Internal malfunction of pressure sensor
P.35C-62
P.35C-19
P.35C-46
35C-7
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Diagnosis code Item
No.
Reference page
C1366
Lateral G-sensor signal error
P.35C-62
C1371
Yaw rate sensor signal error
P.35C-63
C1385
Yaw rate sensor error
P.35C-64
C1387
Lateral G-sensor error
P.35C-65
C1388
Yaw rate sensor active check error
P.35C-66
C1394
Steering wheel sensor neutral point not learned
P.35C-67
C1396
Engine torque intervention rejection
P.35C-67
C1505
Steering wheel sensor error
P.35C-68
C1555
Range exceeding of steering wheel sensor
P.35C-69
C1607
Malfunction of ASC-ECU
P.35C-69
C1621
G and yaw rate sensor improper installation
P.35C-70
C1860
Abnormal rise of ASC-ECU power supply voltage
P.35C-71
C1861
Abnormal drop of ASC-ECU power supply voltage
P.35C-72
C1862
Abnormal power supply voltage of G and yaw rate sensor (high P.35C-75
voltage)
C1863
Abnormal power supply voltage of G and yaw rate sensor (low P.35C-76
voltage)
U1073
Bus-off
P.35C-79
U1100
Engine-related CAN time-out error
P.35C-79
U1104
Steering wheel sensor CAN time-out error
P.35C-80
U1105
G and yaw rate sensor CAN time-out error
P.35C-81
U1406
Accelerator pedal position signal error
P.35C-82
U1426
Engine speed signal error
P.35C-83
U1427
Engine torque signal error
P.35C-84
U1428
Engine's maximum torque signal error
U1429
Engine's minimum torque signal error
U1430
Engine torque request signal error
Main
Index
Group
TOC
35C-8
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
DIAGNOSTIC TROUBLE CODE
PROCEDURES
Main
Index
Code No. C1200: Wheel speed sensor (FR) system (open circuit or short to earth or power supply)
Code No. C1205: Wheel speed sensor (FL) system (open circuit or short to earth or power supply)
Code No. C1210: Wheel speed sensor (RR) system (open circuit or short to earth or power supply)
Code No. C1215 Wheel speed sensor (RL) system (open circuit or short to earth or power supply)
Wheel Speed Sensor Circuit
FRONT WHEEL SPEED SENSOR
(LH)
(RH)
REAR WHEEL SPEED SENSOR
(LH)
(RH)
ASC-ECU
Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
OPERATION
• The wheel speed sensor is a kind of a pulse generator. It consists of magnetic encoders (a plate
on which north and south pole sides of the magnets are arranged alternately) for detecting the
wheel speed which rotates at the same speed of
the wheels and speed sensors. This sensor outputs frequency pulse signals in proportion to the
wheel speed.
• The pulse signals, which the wheel speed sensor
creates, are sent to ASC-ECU. ASC-ECU uses
the frequency of the pulse signals to determine
the wheel speed.
DIAGNOSIS CODE SET CONDITIONS
ASC-ECU monitors voltage fluctuation in each wheel
speed sensor circuit. If the ECU detects short or
open circuit in the circuit, it will set a diagnosis code.
PROBABLE CAUSES
Current trouble
• Damaged wiring harness and connectors
• Malfunction of the wheel speed sensor
• ASC-ECU malfunction
Past trouble
• Carry out diagnosis with particular emphasis on
wiring harness and connector failures between
ASC-ECU and wheel speed sensor. For diagnosis procedures, refer to How to treat past trouble
(GROUP 00 − How to Use Troubleshooting/Inspection Service Points P.00-13).
35C-9
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1200, C1205, C1210 or
C1215 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. M.U.T.-III data list
Check the following service data. (Refer to
P.35B-72.)
• (When the code No. C1200 is set) Item 01: FR
wheel speed sensor
• (When the code No. 1205 is set) Item 02: FL
wheel speed sensor
• (When the code No. 1210 is set) Item 03: RR
wheel speed sensor
• (When the code No. C1215 is set) Item 04: RL
wheel speed sensor
Q: Is the check result normal?
YES : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : Go to Step 4.
Main
Index
Group
TOC
35C-10
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 4. Voltage measurement: A-05 ASC-ECU
connector
Connector: A-05
(2) Ignition switch: ON
(3) Measure the voltage between the power supply
and signal terminals in the wheel speed sensor
circuit and body earth.
Main
Index
Diagnosis code No.
Group
TOC
Power
supply
terminal
Signal
terminal
C1200
No. 29
No. 28
C1205
No. 34
No. 13
C1210
No. 30
No. 8
C1215
No. 11
No. 10
A-05(Black)
Harness side
AC601083 AB
Checking terminal
OK: 0 V
Q: Is the check result normal?
YES : Go to Step 5.
NO (Not normal at the terminal No. 29 or 28) : Go
to Step 6.
NO (Not normal at the terminal No. 34 or 13) : Go
to Step 8.
NO (Not normal at the terminal No. 30 or 8) : Go to
Step 10.
NO (Not normal at the terminal No. 11 or 10) : Go
to Step 12.
MB991984
Check connector
ASC-ECU
ASC-ECU harness connector
AC601085AB
(1) Disconnect the connector, connect the ABS
check harness (Special tool: MB991984) to the
harness-side connector, and measure the voltage
at the special tool connector side.
NOTE: . Do not connect the special tool to
ASC-ECU.
35C-11
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 5. Measure the resistance at A-05 ASC-ECU
connector.
Connector: A-05
(2) Measure the resistance between the power
supply and signal terminals in the wheel speed
sensor circuit and body earth.
Diagnosis code No.
Power
supply
terminal
Signal
terminal
C1200
No. 29
No. 28
C1205
No. 34
No. 13
C1210
No. 30
No. 8
C1215
No. 11
No. 10
A-05(Black)
Harness side
AC601083 AB
Checking terminal
OK: No continuity
Q: Is the check result normal?
YES : Go to Step 14.
NO (Not normal at the terminal No. 29 or 28) : Go
to Step 6.
NO (Not normal at the terminal No. 34 or 13) : Go
to Step 8.
NO (Not normal at the terminal No. 30 or 8) : Go to
Step 10.
NO (Not normal at the terminal No. 11 or 10) : Go
to Step 12.
MB991984
Check connector
STEP 6. Connector check: A-05 ASC-ECU
connector, A-29 wheel speed sensor <FR>
connector
Connector: A-05
ASC-ECU
ASC-ECU harness connector
AC601085AC
(1) Disconnect the connector, connect the ABS
check harness (Special tool: MB991984) to the
harness-side connector, and measure the voltage
at the special tool connector side.
NOTE: Do not connect the special tool to
ASC-ECU.
A-05(Black)
Harness side
AC601083 AB
Connector: A-29
A-29(black)
Harness
side
AC601084 AB
Q: Is the check result normal?
YES : Go to Step 7.
NO : Repair the damaged connector.
Main
Index
Group
TOC
35C-12
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 7. Wiring harness inspection: between
A-05 ASC-ECU connector terminal No. 29, 28 and
A-29 wheel speed sensor <FR> connector
terminal No. 2, 1.
STEP 8. Connector check: A-05 ASC-ECU
connector, A-06 wheel speed sensor <FL>
connector
Connectors: A-05, A-06
A-06: Harness side
Connector: A-05
A-05(Black)
A-05(Black)
A-06 (Black)
A-05:
Harness side
Harness side
AC601083 AC
AC601083 AB
Connector: A-29
A-29(black)
Harness
side
Q: Is the check result normal?
YES : Go to Step 9.
NO : Repair the damaged connector.
STEP 9. Check the harness wire between A-05
ASC-ECU connector terminal No. 34, 13 and A-06
wheel speed sensor <FL> connector terminal No.
2, 1.
Connectors: A-05, A-06
A-06: Harness side
AC601084 AB
Check for short circuit in the wheel speed sensor
<FR> circuit
Q: Is the check result normal?
YES : Replace the wheel speed sensor <FR>.
NO : Repair the wiring harness.
A-05(Black)
A-06 (Black)
A-05:
Harness side
AC601083 AC
Check for short circuit in wheel speed sensor <FL>
circuit.
Q: Is the check result normal?
YES : Replace the wheel speed sensor <FL>.
NO : Repair the wiring harness.
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 10. Connector check: A-05 ASC-ECU
connector, B-41 intermediate connector, C-06
wheel speed sensor <RR> connector
Connector: A-05
35C-13
STEP 11. Wiring harness inspection: between
A-05 ASC-ECU connector terminal No. 30, 8 and
C-06 wheel speed sensor <RR> connector
terminal No. 2, 1.
Connector: A-05
A-05(Black)
A-05(Black)
Harness side
Harness side
AC601083 AB
AC601083 AB
Connector: B-41
Connector: C-06
Harness side
C-06 (Black)
AC601092 AB
AC601093 AB
Connector: C-06
Check for short circuit in wheel speed sensor <RR>
circuit.
Harness side
Q: Is the check result normal?
YES : Replace the wheel speed sensor <RR>.
NO : Repair the wiring harness.
C-06 (Black)
AC601093 AB
Q: Is the check result normal?
YES : Go to Step 11.
NO : Repair the damaged connector.
Main
Index
Group
TOC
35C-14
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 12. Connector check: A-05 ASC-ECU
connector, B-41 intermediate connector, C-17
wheel speed sensor <RL> connector
Connector: A-05
Main
STEP 13. Wiring harness check: between A-05
ASC-ECU connector terminal No. 11, 10 and C-17 Index
wheel speed sensor <RL> connector terminal No.
2, 1.
Group
TOC
Connector: A-05
A-05(Black)
A-05(Black)
Harness side
Harness side
AC601083 AB
AC601083 AB
Connector: B-41
Connector: C-17
Harness side
AC601092 AB
C-17(Black) AC601094AB
Connector: C-17
Harness side
Check for short circuit in wheel speed sensor <RL>
circuit.
Q: Is the check result normal?
YES : Replace the wheel speed sensor <RL>.
NO : Repair the wiring harness.
C-17(Black) AC601094AB
Q: Is the check result normal?
YES : Go to Step 13.
NO : Repair the damaged connector.
35C-15
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 14. Voltage measurement: A-05 ASC-ECU
connector
Diagnosis code No.
Power
supply
terminal
Signal
terminal
C1200
No. 29
No. 28
C1205
No. 34
No. 13
C1210
No. 30
No. 8
C1215
No. 11
No. 10
Connector: A-05
A-05(Black)
Harness side
AC601083 AB
Checking terminal
OK:
<Power supply terminal> Approximately 12
V
<Signal terminal> 0.4 to 1.3 V
Q: Is the check result normal?
YES : Go to Step 24.
NO (Not normal at the terminal No. 29 or 28) : Go
to Step 15.
NO (Not normal at the terminal No. 34 or 13) : Go
to Step 17.
NO (Not normal at the terminal No. 30 or 8) : Go to
Step 19.
NO (Not normal at the terminal No. 11 or 10) : Go
to Step 21.
MB991984
Check connector
STEP 15. Connector check: A-05 ASC-ECU
connector, A-29 wheel speed sensor <FR>
connector
Connector: A-05
ASC-ECU
ASC-ECU harness connector
AC601086AE
(1) Disconnect the connector, connect the ABS
check harness (Special tool: MB991984) to the
ASC-ECU side connector and harness-side
connector, and then measure the voltage at the
special tool connector side.
(2) Ignition switch: ON
(3) Measure the voltage between the power supply
and signal terminals in the wheel speed sensor
circuit and body earth.
A-05(Black)
Harness side
AC601083 AB
Connector: A-29
A-29(black)
Harness
side
AC601084 AB
Q: Is the check result normal?
YES : Go to Step 16.
NO : Repair the damaged connector.
Main
Index
Group
TOC
35C-16
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 16. Wiring harness inspection: between
A-05 ASC-ECU connector terminal No. 29, 28 and
A-29 wheel speed sensor <FR> connector
terminal No. 2, 1.
STEP 17. Connector check: A-05 ASC-ECU
connector, A-06 wheel speed sensor <FL>
connector
Connectors: A-05, A-06
A-06: Harness side
Connector: A-05
A-05(Black)
A-05(Black)
A-06 (Black)
A-05:
Harness side
Harness side
AC601083 AC
AC601083 AB
Connector: A-29
A-29(black)
Harness
side
Q: Is the check result normal?
YES : Go to Step 18.
NO : Repair the damaged connector.
STEP 18. Check the harness wire between A-05
ASC-ECU connector terminal No. 34, 13 and A-06
wheel speed sensor <FL> connector terminal No.
2, 1.
Connectors: A-05, A-06
A-06: Harness side
AC601084 AB
Check for open circuit in wheel speed sensor <FR>
circuit.
Q: Is the check result normal?
YES : Go to Step 23.
NO : Repair the wiring harness.
A-05(Black)
A-06 (Black)
A-05:
Harness side
AC601083 AC
Check for open circuit in wheel speed sensor <FL>
circuit.
Q: Is the check result normal?
YES : Go to Step 23.
NO : Repair the wiring harness.
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 19. Connector check: A-05 ASC-ECU
connector, B-41 intermediate connector, C-06
wheel speed sensor <RR> connector
Connector: A-05
35C-17
STEP 20. Wiring harness inspection: between
A-05 ASC-ECU connector terminal No. 30, 8 and
C-06 wheel speed sensor <RR> connector
terminal No. 2, 1.
Connector: A-05
A-05(Black)
A-05(Black)
Harness side
Harness side
AC601083 AB
AC601083 AB
Connector: B-41
Connector: C-06
Harness side
C-06 (Black)
AC601092 AB
AC601093 AB
Connector: C-06
Q: Is the check result normal?
YES : Go to Step 23.
NO : Repair the wiring harness.
Harness side
C-06 (Black)
AC601093 AB
Q: Is the check result normal?
YES : Go to Step 20.
NO : Repair the damaged connector.
Main
Index
Group
TOC
35C-18
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 21. Connector check: A-05 ASC-ECU
connector, B-41 intermediate connector, C-17
wheel speed sensor <RL> connector
Connector: A-05
Main
STEP 22. Wiring harness check: between A-05
ASC-ECU connector terminal No. 11, 10 and C-17 Index
wheel speed sensor <RL> connector terminal No.
2, 1.
Group
TOC
Connector: A-05
A-05(Black)
A-05(Black)
Harness side
Harness side
AC601083 AB
AC601083 AB
Connector: B-41
Connector: C-17
Harness side
AC601092 AB
C-17(Black) AC601094AB
Connector: C-17
Harness side
Check for short circuit in wheel speed sensor <RL>
circuit.
Q: Is the check result normal?
YES : Go to Step 23.
NO : Repair the wiring harness.
C-17(Black) AC601094AB
Q: Is the check result normal?
YES : Go to Step 22.
NO : Repair the damaged connector.
STEP 23. Check for wheel speed sensor as a
single unit
Refer to P.35B-81.
Q: Is the check result normal?
YES : Go to Step 24.
NO : Replace the wheel speed sensor.
STEP 24. Diagnosis code recheck
Q: Is the diagnosis code No. C1200, C1205, C1210 or
C1215 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
35C-19
Code No. C1201: wheel speed sensor (FR) system (sensor output error)
Code No. C1206: wheel speed sensor (FL) system (sensor output error)
Code No. C1211: wheel speed sensor (RR) system (sensor output error)
Code No. C1216: wheel speed sensor (RL) system (sensor output error)
Wheel Speed Sensor Circuit
FRONT WHEEL SPEED SENSOR
(LH)
(RH)
REAR WHEEL SPEED SENSOR
(LH)
(RH)
ASC-ECU
Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
• The wheel speed sensor is a kind of a pulse generator. It consists of magnetic encoders (a plate
on which north and south pole sides of the magnets are arranged alternately) for detecting the
wheel speed which rotates at the same speed of
the wheels and speed sensors. This sensor out-
puts frequency pulse signals in proportion to the
wheel speed.
• The pulse signals, which the wheel speed sensor
creates, are sent to ASC-ECU. ASC-ECU uses
the frequency of the pulse signals to determine
the wheel speed.
Main
Index
Group
TOC
35C-20
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
DIAGNOSIS CODE SET CONDITIONS
The ASC-ECU monitors the signals from each wheel
speed sensor while the vehicle is being driven. If any
faults below is found in these sensor signals, the
ECU will set the relevant diagnosis code.
• Missing sensor signal
• Sensor signal, which will not be created under
normal operation
• Significant difference among the wheel speed
sensor signals
PROBABLE CAUSES
Current trouble
• Improper installation of the wheel speed sensor
• Adhesion of foreign materials on the wheel speed
detection magnetic encoder
• Deformation of the wheel speed detection magnetic encoder
• Excessive gap between the wheel speed sensor
and the wheel speed detection magnetic encoder
• Damaged wiring harness and connectors
• Malfunction of the wheel speed sensor
• ASC-ECU malfunction
Past trouble
• When the diagnosis code No. C1200, C1205,
C1210 or C1215 is also set, carry out diagnosis
with particular emphasis on wiring harness and
connector failures between ASC-ECU and wheel
speed sensor. For diagnosis procedures, refer to
How to treat past trouble (GROUP 00 − How to
Use Troubleshooting/Inspection Service Points
P.00-13).
• When the diagnosis code No. C1200, C1205,
C1210, or C1215 is not set, the following conditions may be present:
• Right or/and left wheels are rotated.
• Unstable vehicle attitude
• External noise interference
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No.C1201, C1206, C1211 or
C1216 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. M.U.T.-III diagnosis code
Check that the diagnosis codes No. C1200, C1205,
C1210, and C1215 are also set.
Q: Are the diagnosis codes No. C1200, C1205, C1210
and C1215 also set?
YES : Perform the diagnosis for the diagnosis
code No. C1200, C1205, C1210, and
C1215. (Refer to P.35C-8.)
NO : Go to Step 4.
STEP 4. Wheel speed sensor installation state
check
Check the installation state (sensor disconnection,
loose mounting bolts, etc.) of the wheel speed sensor indicated by the diagnosis code No.
Diagnosis code No.
Relevant
sensor
C1201
Front right
C1206
Front left
C1211
Rear right
C1216
Rear left
Q: Is the check result normal?
YES : Go to Step 5.
NO : Reinstall the wheel speed sensor correctly.
STEP 5. Check for wheel speed sensor as a
single unit
Refer to P.35B-81.
Q: Is the check result normal?
YES : Go to Step 6.
NO : Replace the wheel speed sensor.
Main
Index
Group
TOC
35C-21
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 6. Check for wheel bearing looseness
NOTE: Loose wheel bearing may increase the gap
between the wheel speed sensor and the wheel
speed detection magnet encoder. Check the wheel
bearing indicated by the code No. for looseness.
Diagnosis code No.
Relevant
sensor
C1201
Front right
C1206
Front left
C1211
Rear right
C1216
Rear left
• Front: Refer to GROUP 26 − On-vehicle Service
P.26-5.
• Rear: Refer to GROUP 27A − On-vehicle Service
P.27-3.
STEP 7. Wheel speed detection magnetic
encoder check
<Front>
Group
TOC
Encoder
<Rear>
Q: Is the check result normal?
YES : Go to Step 7.
NO <when the relevant wheel is front> : Replace
the wheel bearing. (Refer to GROUP 26 −
Front Axle Hub P.26-13.)
NO <when the relevant wheel is rear> : Replace
the rear hub assembly. (Refer to GROUP
27A − Rear Axle Hub P.27-6.)
Main
Index
Encoder
AC600965AB
Check the wheel speed detection magnetic encoder
for adhesion of foreign materials or deformation.
NOTE: For the rear wheel speed detection magnetic
encoder, check from the mounting hole of the wheel
speed sensor by rotating the rear hub.
Q: Is the check result normal?
YES : Go to Step 8.
NO <when the relevant wheel is front> : When a
foreign material adheres to the encoder,
clean it. When the encoder is deformed,
replace the wheel bearing. (Refer to
GROUP 26 − Front Axle Hub P.26-13.)
NO <when the relevant wheel is rear> : When a
foreign material adheres to the encoder,
clean it. When the encoder is deformed,
replace the rear hub assembly. (Refer to
GROUP 27A − Rear Axle Hub P.27-6.)
35C-22
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 8. Voltage measurement: A-05 ASC-ECU
connector
Connector: A-05
(2) Ignition switch: ON
(3) Measure the voltage between the power supply
and signal terminals in the wheel speed sensor
circuit and body earth.
Main
Index
Diagnosis code No.
Group
TOC
Power
supply
terminal
Signal
terminal
C1201
No. 29
No. 28
C1206
No. 34
No. 13
C1211
No. 30
No. 8
C1216
No. 11
No. 10
A-05(Black)
Harness side
AC601083 AB
Checking terminal
OK: 0 V
Q: Is the check result normal?
YES : Go to Step 9.
NO (Not normal at the terminal No. 29 or 28) : Go
to Step 10.
NO (Not normal at the terminal No. 34 or 13) : Go
to Step 11.
NO (Not normal at the terminal No. 30 or 8) : Go to
Step 12.
NO (Not normal at the terminal No. 11 or 10) : Go
to Step 13.
MB991984
Check connector
ASC-ECU
ASC-ECU harness connector
AC601085AB
(1) Disconnect the connector, connect the ABS
check harness (Special tool: MB991984) to the
harness-side connector, and measure the voltage
at the special tool connector side.
NOTE: . Do not connect the special tool to
ASC-ECU.
35C-23
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 9. Measure the resistance at A-05 ASC-ECU
connector.
Diagnosis code No.
Power
supply
terminal
Signal
terminal
C1201
No. 29
No. 28
C1206
No. 34
No. 13
C1211
No. 30
No. 8
C1216
No. 11
No. 10
Connector: A-05
A-05(Black)
Harness side
Checking terminal
OK: No continuity
AC601083 AB
Q: Is the check result normal?
YES : Go to Step 14.
NO (Not normal at the terminal No. 29 or 28) : Go
to Step 10.
NO (Not normal at the terminal No. 34 or 13) : Go
to Step 11.
NO (Not normal at the terminal No. 30 or 8) : Go to
Step 12.
NO (Not normal at the terminal No. 11 or 10) : Go
to Step 13.
STEP 10. Connector check: A-05 ASC-ECU
connector, A-29 wheel speed sensor <FR>
connector
Connector: A-05
MB991984
Check connector
ASC-ECU
A-05(Black)
Harness side
ASC-ECU harness connector
AC601085AC
(1) Disconnect the connector, connect the ABS
check harness (Special tool: MB991984) to the
harness-side connector, and measure the voltage
at the special tool connector side.
NOTE: Do not connect the special tool to
ASC-ECU.
(2) Measure the resistance between the power
supply and signal terminals in the wheel speed
sensor circuit and body earth.
AC601083 AB
Connector: A-29
A-29(black)
Harness
side
AC601084 AB
Q: Is the check result normal?
YES : Go to Step 16.
NO : Repair the damaged connector.
Main
Index
Group
TOC
35C-24
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 11. Connector check: A-05 ASC-ECU
connector, A-06 wheel speed sensor <FL>
connector
Connectors: A-05, A-06
A-05(Black)
A-06: Harness side
A-06 (Black)
A-05:
Harness side
STEP 12. Connector check: A-05 ASC-ECU
connector, B-41 intermediate connector, C-06
wheel speed sensor <RR> connector
Connector: A-05
Group
TOC
A-05(Black)
Harness side
AC601083 AC
Q: Is the check result normal?
YES : Go to Step 18.
NO : Repair the damaged connector.
Main
Index
AC601083 AB
Connector: B-41
AC601092 AB
Connector: C-06
Harness side
C-06 (Black)
AC601093 AB
Q: Is the check result normal?
YES : Go to Step 20.
NO : Repair the damaged connector.
35C-25
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 13. Connector check: A-05 ASC-ECU
connector, B-41 intermediate connector, C-17
wheel speed sensor <RL> connector
STEP 14. Voltage measurement: A-05 ASC-ECU
connector
Main
Index
Connector: A-05
Connector: A-05
Group
TOC
A-05(Black)
A-05(Black)
Harness side
Harness side
AC601083 AB
AC601083 AB
Connector: B-41
AC601092 AB
Connector: C-17
Harness side
MB991984
Check connector
ASC-ECU
ASC-ECU harness connector
C-17(Black) AC601094AB
Q: Is the check result normal?
YES : Go to Step 22.
NO : Repair the damaged connector.
AC601086AE
(1) Disconnect the connector, connect the ABS
check harness (Special tool: MB991984) to the
ASC-ECU side connector and harness-side
connector, and then measure the voltage at the
special tool connector side.
(2) Ignition switch: ON
(3) Measure the voltage between the power supply
and signal terminals in the wheel speed sensor
circuit and body earth.
35C-26
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Diagnosis code No.
Checking terminal
Power
supply
terminal
Signal
terminal
C1201
No. 29
No. 28
C1206
No. 34
No. 13
C1211
No. 30
No. 8
C1216
No. 11
No. 10
OK:
<Power supply terminal> Approximately 12
V
<Signal terminal> 0.4 to 1.3 V
Q: Is the check result normal?
YES : Go to Step 23.
NO (Not normal at the terminal No. 29 or 28) : Go
Main
STEP 16. Wiring harness inspection: between
A-05 ASC-ECU connector terminal No. 29, 28 and Index
A-29 wheel speed sensor <FR> connector
terminal No. 2, 1.
Group
TOC
Connector: A-05
A-05(Black)
Harness side
AC601083 AB
Connector: A-29
to Step 15.
NO (Not normal at the terminal No. 34 or 13) : Go
to Step 17.
A-29(black)
NO (Not normal at the terminal No. 30 or 8) : Go to
Harness
side
Step 19.
NO (Not normal at the terminal No. 11 or 10) : Go
to Step 21.
AC601084 AB
STEP 15. Connector check: A-05 ASC-ECU
connector, A-29 wheel speed sensor <FR>
connector
Connector: A-05
Check for short and open circuit in wheel speed sensor <FR> circuit
Q: Is the check result normal?
YES : Go to Step 23.
NO : Repair the wiring harness.
STEP 17. Connector check: A-05 ASC-ECU
connector, A-06 wheel speed sensor <FL>
connector
A-05(Black)
Harness side
Connectors: A-05, A-06
A-06: Harness side
AC601083 AB
Connector: A-29
A-05(Black)
A-06 (Black)
A-05:
Harness side
A-29(black)
Harness
side
AC601084 AB
Q: Is the check result normal?
YES : Go to Step 16.
NO : Repair the damaged connector.
AC601083 AC
Q: Is the check result normal?
YES : Go to Step 18.
NO : Repair the damaged connector.
35C-27
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 18. Check the harness wire between A-05
ASC-ECU connector terminal No. 34, 13 and A-06
wheel speed sensor <FL> connector terminal No.
2, 1.
Connectors: A-05, A-06
STEP 19. Connector check: A-05 ASC-ECU
connector, B-41 intermediate connector, C-06
wheel speed sensor <RR> connector
Connector: A-05
Group
TOC
A-06: Harness side
A-05(Black)
A-05(Black)
A-06 (Black)
Harness side
A-05:
Harness side
AC601083 AB
AC601083 AC
Check for short and open circuit in wheel speed sensor <FL> circuit
Main
Index
Connector: B-41
Q: Is the check result normal?
YES : Go to Step 23.
NO : Repair the wiring harness.
AC601092 AB
Connector: C-06
Harness side
C-06 (Black)
AC601093 AB
Q: Is the check result normal?
YES : Go to Step 20.
NO : Repair the damaged connector.
35C-28
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 20. Wiring harness inspection: between
A-05 ASC-ECU connector terminal No. 11, 10 and
C-06 wheel speed sensor <RR> connector
terminal No. 2, 1.
STEP 21. Connector check: A-05 ASC-ECU
connector, B-41 intermediate connector, C-17
wheel speed sensor <RL> connector
Connector: A-05
Group
TOC
Connector: A-05
A-05(Black)
A-05(Black)
Harness side
Harness side
AC601083 AB
AC601083 AB
Connector: B-41
Connector: C-06
Harness side
C-06 (Black)
AC601092 AB
AC601093 AB
Check for short and open circuit in wheel speed sensor <RR> circuit
Main
Index
Connector: C-17
Harness side
Q: Is the check result normal?
YES : Go to Step 23.
NO : Repair the wiring harness.
C-17(Black) AC601094AB
Q: Is the check result normal?
YES : Go to Step 22.
NO : Repair the damaged connector.
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 22. Wiring harness check: between A-05
ASC-ECU connector terminal No. 11, 10 and C-17
wheel speed sensor <RL> connector terminal No.
2, 1.
35C-29
STEP 23. ABS warning lamp OFF recheck
Drive the vehicle until the vehicle speed reaches
30km/h and check that the ABS warning lamp goes
out.
Q: Does the ABS warning lamp extinguish?
YES : Go to Step 25.
NO : Replace the ASC-ECU, and then go to Step
Connector: A-05
24.
A-05(Black)
STEP 24. ABS warning lamp OFF recheck
Drive the vehicle until the vehicle speed reaches
30km/h and check that the ABS warning lamp goes
out.
Harness side
AC601083 AB
Connector: C-17
Harness side
C-17(Black) AC601094AB
Check for short and open circuit in wheel speed sensor <RL> circuit
Q: Is the check result normal?
YES : Go to Step 23.
NO : Repair the wiring harness.
Q: Does the ABS warning lamp extinguish?
YES : Go to Step 25.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
STEP 25. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is the diagnosis code No.C1201, C1206, C1211 or
C1216 set?
YES : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : This diagnosis is complete.
Main
Index
Group
TOC
35C-30
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Code No. C1222: Wheel speed sensor system (abnormal power supply voltage)
Wheel Speed Sensor Circuit
FRONT WHEEL SPEED SENSOR
(LH)
(RH)
REAR WHEEL SPEED SENSOR
(LH)
(RH)
ASC-ECU
Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
The wheel speed sensors are energised by
ASC-ECU. If an abnormality occurs in this power
supply voltage, this diagnosis code is set.
PROBABLE CAUSES
• Short-circuited wheel speed sensor circuit and
power supply circuit
• ASC-ECU malfunction
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
Main
Index
Group
TOC
35C-31
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1222 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. Voltage measurement: A-05 ASC-ECU
connector
Connector: A-05
Wheel speed sensor Checking terminal
position
Power
Signal
supply
terminal
terminal
Right front wheel
No. 29
No. 28
Left front wheel
No. 34
No. 13
Right rear wheel
No. 30
No. 8
Left rear wheel
No. 11
No. 10
OK: 0 V
Q: Is the check result normal?
YES : Go to Step 12.
NO (Not normal at the terminal No. 29 or 28) : Go
A-05(Black)
to Step 4.
NO (Not normal at the terminal No. 34 or 13) : Go
Harness side
to Step 6.
NO (Not normal at the terminal No. 30 or 8) : Go to
AC601083 AB
Step 8.
NO (Not normal at the terminal No. 11 or 10) : Go
to Step 10.
STEP 4. Connector check: A-05 ASC-ECU
connector, A-29 wheel speed sensor <FR>
connector
Connector: A-05
A-05(Black)
Harness side
MB991984
Check connector
ASC-ECU
ASC-ECU harness connector
AC601085AB
(1) Disconnect the connector, connect the ABS
check harness (Special tool: MB991984) to the
harness-side connector, and measure the voltage
at the special tool connector side.
NOTE: Do not connect the special tool to
ASC-ECU.
(2) Ignition switch: ON
(3) Measure the voltage between the power supply
and signal terminals in the wheel speed sensor
circuit and body earth.
AC601083 AB
Connector: A-29
A-29(black)
Harness
side
AC601084 AB
Q: Is the check result normal?
YES : Go to Step 5.
NO : Repair the damaged connector.
Main
Index
Group
TOC
35C-32
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 5. Wiring harness inspection: between
A-05 ASC-ECU connector terminal No. 29, 28 and
A-29 wheel speed sensor <FR> connector
terminal No. 2, 1.
STEP 6. Connector check: A-05 ASC-ECU
connector, A-06 wheel speed sensor <FL>
connector
Connectors: A-05, A-06
A-06: Harness side
Connector: A-05
A-05(Black)
A-05(Black)
A-06 (Black)
A-05:
Harness side
Harness side
AC601083 AC
AC601083 AB
Connector: A-29
A-29(black)
Harness
side
Q: Is the check result normal?
YES : Go to Step 7.
NO : Repair the damaged connector.
STEP 7. Check the harness wire between A-05
ASC-ECU connector terminal No. 34, 13 and A-06
wheel speed sensor <FL> connector terminal No.
2, 1.
Connectors: A-05, A-06
A-06: Harness side
AC601084 AB
Check for short and open circuit in wheel speed sensor <FR> circuit
Q: Is the check result normal?
YES : Go to Step 12.
NO : Repair the wiring harness.
A-05(Black)
A-06 (Black)
A-05:
Harness side
AC601083 AC
Check for short and open circuit in wheel speed sensor <FL> circuit
Q: Is the check result normal?
YES : Go to Step 12.
NO : Repair the wiring harness.
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 8. Connector check: A-05 ASC-ECU
connector, B-41 intermediate connector, C-06
wheel speed sensor <RR> connector
Q: Is the check result normal?
35C-33
Main
STEP 9. Wiring harness inspection: between
A-05 ASC-ECU connector terminal No. 11, 10 and Index
C-06 wheel speed sensor <RR> connector
terminal No. 2, 1.
Group
TOC
Connector: A-05
Connector: A-05
A-05(Black)
A-05(Black)
Harness side
Harness side
AC601083 AB
AC601083 AB
Connector: C-06
Connector: B-41
Harness side
C-06 (Black)
AC601093 AB
AC601092 AB
Check for short and open circuit in wheel speed sensor <RR> circuit
Connector: C-06
Q: Is the check result normal?
YES : Go to Step 12.
NO : Repair the wiring harness.
Harness side
C-06 (Black)
AC601093 AB
YES : Go to Step 9.
NO : Repair the damaged connector.
35C-34
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 10. Connector check: A-05 ASC-ECU
connector, B-41 intermediate connector, C-17
wheel speed sensor <RL> connector
Connector: A-05
Main
STEP 11. Wiring harness check: between A-05
ASC-ECU connector terminal No. 11, 10 and C-17 Index
wheel speed sensor <RL> connector terminal No.
2, 1.
Group
TOC
Connector: A-05
A-05(Black)
A-05(Black)
Harness side
Harness side
AC601083 AB
AC601083 AB
Connector: B-41
Connector: C-17
Harness side
AC601092 AB
C-17(Black) AC601094AB
Connector: C-17
Harness side
Check for short and open circuit in wheel speed sensor <RL> circuit
Q: Is the check result normal?
YES : Go to Step 12.
NO : Repair the wiring harness.
STEP 12. Diagnosis code recheck
C-17(Black) AC601094AB
Q: Is the check result normal?
YES : Go to Step 11.
NO : Repair the damaged connector.
Q: Is diagnosis code No. C1222 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
35C-35
Main
Index
Code No. C1225: Wheel speed sensor system (sensor output error)
Wheel Speed Sensor Circuit
FRONT WHEEL SPEED SENSOR
(LH)
(RH)
REAR WHEEL SPEED SENSOR
(LH)
(RH)
ASC-ECU
Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
• The wheel speed sensor is a kind of a pulse generator. It consists of magnetic encoders (a plate
on which north and south pole sides of the magnets are arranged alternately) for detecting the
wheel speed which rotates at the same speed of
the wheels and speed sensors. This sensor outputs frequency pulse signals in proportion to the
wheel speed.
• The pulse signals, which the wheel speed sensor
creates, are sent to ASC-ECU. ASC-ECU uses
the frequency of the pulse signals to determine
the wheel speed.
Group
TOC
35C-36
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
DIAGNOSIS CODE SET CONDITIONS
The ASC-ECU monitors the signals from each wheel
speed sensor. If any faults below is found in this sensor signal, the ECU will set the relevant diagnosis
code. When the abnormal wheel is identified, the
diagnosis code No. C1201, C1206, C1211, or C1216
is set.
• Missing sensor signal
• Sensor signal, which will not be created under
normal operation
• Significant difference among the wheel speed
sensor signals
• Continuous ABS or ASC control for one minute or
more
PROBABLE CAUSES
Current trouble
• Improper installation of the wheel speed sensor
• Adhesion of foreign materials on the wheel speed
detection magnetic encoder
• Deformation of the wheel speed detection magnetic encoder
• Excessive gap between the wheel speed sensor
and the wheel speed detection magnetic encoder
• Damaged wiring harness and connectors
• Malfunction of the wheel speed sensor
• ASC-ECU malfunction
Past trouble
• The following conditions may occur.
• Right or/and left wheels are rotated.
• Unstable vehicle attitude
• External noise interference
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D, Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the relevant diagnosis code No. C1225 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. Wheel speed sensor installation state
check
Check the installation state (sensor disconnection,
loose mounting bolts, etc.) of the wheel speed sensor for every wheel.
Q: Is the check result normal?
YES : Go to Step 4.
NO : Reinstall the wheel speed sensor correctly.
STEP 4. Check for wheel speed sensor as a
single unit
Refer to P.35B-81.
Q: Is the check result normal?
YES : Go to Step 5.
NO : Replace the wheel speed sensor.
STEP 5. Check for wheel bearing looseness
NOTE: Loose wheel bearing may increase the gap
between the wheel speed sensor and the wheel
speed detection magnet encoder. Check each wheel
bearing for looseness.
• Front: Refer to GROUP 26 − On-vehicle Service
P.26-5.
• Rear: Refer to GROUP 27A − On-vehicle Service
P.27-3.
Q: Is the check result normal?
YES : Go to Step 6.
NO <when the relevant wheel is front> : Replace
the wheel bearing. (Refer to GROUP 26 −
Front Axle Hub P.26-13.)
NO <when the relevant wheel is rear> : Replace
the rear hub assembly. (Refer to GROUP
27A − Rear Axle Hub P.27-6.)
Main
Index
Group
TOC
35C-37
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 6. Wheel speed detection magnetic
encoder check
STEP 7. Voltage measurement: A-05 ASC-ECU
connector
Main
Index
Connector: A-05
<Front>
Group
TOC
A-05(Black)
Harness side
Encoder
AC601083 AB
<Rear>
Encoder
AC600965AB
Check the wheel speed detection magnetic encoder
for adhesion of foreign materials or deformation.
NOTE: For the rear wheel speed detection magnetic
encoder, check from the mounting hole of the wheel
speed sensor by rotating the rear hub.
MB991984
Q: Is the check result normal?
YES : Go to Step 7.
NO <when the relevant wheel is front> : When a
foreign material adheres to the encoder,
clean it. When the encoder is deformed,
replace the wheel bearing. (Refer to
GROUP 26 − Front Axle Hub P.26-13.)
NO <when the relevant wheel is rear> : When a
foreign material adheres to the encoder,
clean it. When the encoder is deformed,
replace the rear hub assembly. (Refer to
GROUP 27A − Rear Axle Hub P.27-6.)
Check connector
ASC-ECU
ASC-ECU harness connector
AC601085AB
(1) Disconnect the connector, connect the ABS
check harness (Special tool: MB991984) to the
harness-side connector, and measure the voltage
at the special tool connector side.
NOTE: Do not connect the special tool to
ASC-ECU.
(2) Ignition switch: ON
(3) Measure the voltage between the power supply
and signal terminals in the wheel speed sensor
circuit and body earth.
35C-38
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Wheel speed sensor Checking terminal
position
Power
Signal
supply
terminal
terminal
Right front wheel
No. 29
No. 28
Left front wheel
No. 34
No. 13
Right rear wheel
No. 30
No. 8
Left rear wheel
No. 11
No. 10
Main
STEP 8. Measure the resistance at A-05 ASC-ECU
Index
connector.
Connector: A-05
Group
TOC
A-05(Black)
Harness side
OK: 0 V
Q: Is the check result normal?
YES : Go to Step 8.
NO (Not normal at the terminal No. 29 or 28) : Go
AC601083 AB
to Step 9.
NO (Not normal at the terminal No. 34 or 13) : Go
to Step 10.
NO (Not normal at the terminal No. 30 or 8) : Go to
Step 11.
NO (Not normal at the terminal No. 11 or 10) : Go
to Step 12.
MB991984
Check connector
ASC-ECU
ASC-ECU harness connector
AC601085AC
(1) Disconnect the connector, connect the ABS
check harness (Special tool: MB991984) to the
harness-side connector, and measure the voltage
at the special tool connector side.
NOTE: Do not connect the special tool to
ASC-ECU.
(2) Measure the resistance between the power
supply and signal terminals in the wheel speed
sensor circuit and body earth.
35C-39
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Wheel speed sensor Checking terminal
position
Power
Signal
supply
terminal
terminal
Right front wheel
No. 29
No. 28
Left front wheel
No. 34
No. 13
Right rear wheel
No. 30
No. 8
Left rear wheel
No. 11
No. 10
OK: No continuity
STEP 9. Connector check: A-05 ASC-ECU
connector, A-29 wheel speed sensor <FR>
connector
Connector: A-05
to Step 9.
Group
TOC
A-05(Black)
Harness side
Q: Is the check result normal?
YES : Go to Step 13.
NO (Not normal at the terminal No. 29 or 28) : Go
AC601083 AB
Connector: A-29
NO (Not normal at the terminal No. 34 or 13) : Go
to Step 10.
NO (Not normal at the terminal No. 30 or 8) : Go to
Step 11.
A-29(black)
NO (Not normal at the terminal No. 11 or 10) : Go
Harness
side
to Step 12.
AC601084 AB
Q: Is the check result normal?
YES : Go to Step 15.
NO : Repair the damaged connector.
STEP 10. Connector check: A-05 ASC-ECU
connector, A-06 wheel speed sensor <FL>
connector
Connectors: A-05, A-06
A-05(Black)
Main
Index
A-06: Harness side
A-06 (Black)
A-05:
Harness side
AC601083 AC
Q: Is the check result normal?
YES : Go to Step 17.
NO : Repair the damaged connector.
35C-40
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 11. Connector check: A-05 ASC-ECU
connector, B-41 intermediate connector, C-06
wheel speed sensor <RR> connector
Connector: A-05
STEP 12. Connector check: A-05 ASC-ECU
connector, B-41 intermediate connector, C-17
wheel speed sensor <RL> connector
Connector: A-05
A-05(Black)
Group
TOC
A-05(Black)
Harness side
Harness side
AC601083 AB
Connector: B-41
AC601083 AB
Connector: B-41
AC601092 AB
Connector: C-06
AC601092 AB
Connector: C-17
Harness side
Harness side
C-06 (Black)
AC601093 AB
Q: Is the check result normal?
YES : Go to Step 19.
NO : Repair the damaged connector.
Main
Index
C-17(Black) AC601094AB
Q: Is the check result normal?
YES : Go to Step 21.
NO : Repair the damaged connector.
35C-41
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 13. Voltage measurement: A-05 ASC-ECU
connector
Connector: A-05
A-05(Black)
Harness side
AC601083 AB
Wheel speed sensor Checking terminal
position
Power
Signal
supply
terminal
terminal
Right front wheel
No. 29
No. 28
Left front wheel
No. 34
No. 13
Right rear wheel
No. 30
No. 8
Left rear wheel
No. 11
No. 10
OK:
<Power supply terminal> Approximately 12
V
<Signal terminal> 0.4 to 1.3 V
Q: Is the check result normal?
YES : Go to Step 22.
NO (Not normal at the terminal No. 29 or 28) : Go
to Step 14.
NO (Not normal at the terminal No. 34 or 13) : Go
to Step 16.
NO (Not normal at the terminal No. 30 or 8) : Go to
Step 18.
NO (Not normal at the terminal No. 11 or 10) : Go
to Step 20.
MB991984
Check connector
STEP 14. Connector check: A-05 ASC-ECU
connector, A-29 wheel speed sensor <FR>
connector
Connector: A-05
ASC-ECU
ASC-ECU harness connector
AC601085AB
(1) Disconnect the connector, connect the ABS
check harness (Special tool: MB991984) to the
ASC-ECU side connector and harness-side
connector, and then measure the voltage at the
special tool connector side.
(2) Ignition switch: ON
(3) Measure the voltage between the power supply
and signal terminals in the wheel speed sensor
circuit and body earth.
A-05(Black)
Harness side
AC601083 AB
Connector: A-29
A-29(black)
Harness
side
AC601084 AB
Q: Is the check result normal?
YES : Go to Step 15.
NO : Repair the damaged connector.
Main
Index
Group
TOC
35C-42
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 15. Wiring harness inspection: between
A-05 ASC-ECU connector terminal No. 29, 28 and
A-29 wheel speed sensor <FR> connector
terminal No. 2, 1.
STEP 16. Connector check: A-05 ASC-ECU
connector, A-06 wheel speed sensor <FL>
connector
Connectors: A-05, A-06
A-06: Harness side
Connector: A-05
A-05(Black)
A-05(Black)
A-06 (Black)
A-05:
Harness side
Harness side
AC601083 AC
AC601083 AB
Connector: A-29
A-29(black)
Harness
side
Q: Is the check result normal?
YES : Go to Step 17.
NO : Repair the damaged connector.
STEP 17. Check the harness wire between A-05
ASC-ECU connector terminal No. 34, 13 and A-06
wheel speed sensor <FL> connector terminal No.
2, 1.
Connectors: A-05, A-06
A-06: Harness side
AC601084 AB
Check for short and open circuit in wheel speed sensor <FR> circuit
Q: Is the check result normal?
YES : Go to Step 22.
NO : Repair the wiring harness.
A-05(Black)
A-06 (Black)
A-05:
Harness side
AC601083 AC
Check for short and open circuit in wheel speed sensor <FL> circuit
Q: Is the check result normal?
YES : Go to Step 22.
NO : Repair the wiring harness.
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 18. Connector check: A-05 ASC-ECU
connector, B-41 intermediate connector, C-06
wheel speed sensor <RR> connector
Connector: A-05
35C-43
STEP 19. Wiring harness inspection: between
A-05 ASC-ECU connector terminal No. 30, 8 and
C-06 wheel speed sensor <RR> connector
terminal No. 2, 1.
Connector: A-05
A-05(Black)
A-05(Black)
Harness side
Harness side
AC601083 AB
AC601083 AB
Connector: B-41
Connector: C-06
Harness side
C-06 (Black)
AC601092 AB
AC601093 AB
Connector: C-06
Check for short and open circuit in wheel speed sensor <RR> circuit
Harness side
Q: Is the check result normal?
YES : Go to Step 22.
NO : Repair the wiring harness.
C-06 (Black)
AC601093 AB
Q: Is the check result normal?
YES : Go to Step 19.
NO : Repair the damaged connector.
Main
Index
Group
TOC
35C-44
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 20. Connector check: A-05 ASC-ECU
connector, B-41 intermediate connector, C-17
wheel speed sensor <RL> connector
Connector: A-05
Main
STEP 21. Wiring harness check: between A-05
ASC-ECU connector terminal No. 11, 10 and C-17 Index
wheel speed sensor <RL> connector terminal No.
2, 1.
Group
TOC
Connector: A-05
A-05(Black)
A-05(Black)
Harness side
Harness side
AC601083 AB
AC601083 AB
Connector: B-41
Connector: C-17
Harness side
AC601092 AB
C-17(Black) AC601094AB
Connector: C-17
Harness side
Check for short and open circuit in wheel speed sensor <RL> circuit
Q: Is the check result normal?
YES : Go to Step 22.
NO : Repair the wiring harness.
C-17(Black) AC601094AB
Q: Is the check result normal?
YES : Go to Step 21.
NO : Repair the damaged connector.
STEP 22. ABS warning lamp OFF recheck
Drive the vehicle until the vehicle speed reaches
30km/h and check that the ABS warning lamp goes
out.
Q: Does the ABS warning lamp extinguish?
YES : Go to Step 24.
NO : Replace the ASC-ECU, and then go to Step
23.
STEP 23. ABS warning lamp OFF recheck
Drive the vehicle until the vehicle speed reaches
30km/h and check that the ABS warning lamp goes
out.
Q: Does the ABS warning lamp extinguish?
YES : Go to Step 24.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
35C-45
Main
Index
STEP 24. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Group
TOC
Q: Is the diagnosis code No. C1225 set?
YES : . Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : . This diagnosis is complete.
Code No. C1226: Control solenoid valve (FR) pressure holding system
Code No. C1231: Control solenoid valve (FR) decompressing system
Code No. C1236: Control solenoid valve (FL) pressure holding system
Code No. C1241: Control solenoid valve (FL) pressure reducing system
Code No. C1246: Control solenoid valve (RR) pressure holding system
Code No. C1251: Control solenoid valve (RR) pressure reducing system
Code No. C1256: Control solenoid valve (RL) pressure holding system
Code No. C1261: Control solenoid valve (RL) decompressing system
Code No. C1300: Cut valve (FR/RL) <primary> system
Code No. C1305: Suction valve (FR/RL) <primary> system
Code No. C1310: Cut valve (FL/RR) <secondary> system
Code No. C1315: Suction valve (FL/RR) <secondary> system
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
• ASC-ECU contains the power supply circuit (terminal No. 44) for the solenoid valve, cut valve,
and suction valve. The solenoid valve, cut valve,
and suction valve are energised by the valve
relay, which is incorporated in ASC-ECU.
• The valve relay, which is incorporated in
ASC-ECU, is energising the solenoid valve, cut
valve, ad suction valve unless the initial check is
in progress when the ignition switch is turned on,
or the recurrent system check is in progress.
• ASC-ECU activates the solenoid valve by turning
on its driving transistor.
DIAGNOSIS CODE SET CONDITIONS
Code No. C1226, C1231, C1236, C1241, C1246,
C1251, C1256 and C1261.
• These codes are set when the ASC-ECU drive
signal does not match the feed back signal from
the solenoid valve.
Code No. C1300, C1305, C1310, and C1315
• These codes are set when an abnormality is
detected in ASC-ECU.
PROBABLE CAUSES
• Damaged wiring harness and connectors
• ASC-ECU malfunction
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Replace the ASC-ECU.
NO : Repair the CAN bus lines. (Refer to GROUP
54D, Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Are the diagnosis code C1226, C1231, C1236,
C1241, C1246, C1251, C1256, C1261, C1300, C1305,
C1310, and C1315 set?
YES : Replace the ASC-ECU.
NO : This diagnosis is complete.
35C-46
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Main
Index
Code No. C1266: Motor relay seizure
Code No. C1273: Motor relay stuck OFF
Code No. C1274: Motor relay stuck ON
Hydraulic unit (Motor and Solenoid Valve) Circuit
FUSIBLE
LINK 5
FUSIBLE
LINK 3
HYDRAULIC UNIT
MOTOR
SOLENOID
VALVE
POWER
SOURCE
ABS SOLENOID VALVE
MOTOR
POWER
SOURCE
ASC-ECU
Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
• ASC-ECU contains the power supply circuit (terminal 45) for the pump motor. The pump motor is
energised by the motor relay, which is incorporated in ASC-ECU.
• The motor relay, which is incorporated in
ASC-ECU, is always off unless the motor solenoid valve check is activated when the vehicle is
started.
• ASC-ECU activates the pump motor by turning
on the ECU built-in motor relay when ABS or
ASC is working.
Group
TOC
35C-47
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
DIAGNOSIS CODE SET CONDITIONS
These diagnostic trouble codes will be set under the
cases below.
Code No. C1266: Motor relay seizure
• The ABS-ECU monitors the voltage, which is created by the pump motor coasting, after the motor
relay is turned off. If the voltage continues only for
too short period, the ECU determines that the
pump motor is not running smoothly (i.e. motor
seizure), and sets this diagnosis code.
STEP 3. Voltage measurement: A-05 ASC-ECU
connector
Connector: A-05
Group
TOC
A-05(Black)
Harness side
Code No. C1273: Motor relay stuck OFF
• If the voltage, which is created by the pump
motor, is abnormal after the motor relay is turned
on, the ECU determines that the motor relay is
stuck off, and sets this diagnosis code.
AC601083 AB
Code No. C1274: Motor relay stuck ON
• If the voltage, which is created by the pump
motor, is abnormal after the motor relay is turned
off, the ECU determines that the motor relay is
stuck on, and sets this diagnosis code.
PROBABLE CAUSES
Current trouble
• Damaged wiring harness and connectors
• ASC-ECU malfunction
Past trouble
• Carry out diagnosis with particular emphasis on
connector(s) or wiring harness between the
power supply circuit (terminal 45) to the
ASC-ECU motor or earth circuit (terminal 46). For
diagnosis procedures, refer to How to treat past
trouble (GROUP 00 − How to Use Troubleshooting/Inspection Service Points P.00-13).
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Has diagnosis code C1266, C1273 or C1274 been
set?
YES : Go to Step 3.
NO : This diagnosis is complete.
Main
Index
MB991984
Check connector
ASC-ECU
ASC-ECU harness connector
AC601085AD
(1) Disconnect the connector, connect the ABS
check harness (Special tool: MB991984) to the
harness-side connector, and measure the voltage
at the special tool connector side.
NOTE: Do not connect the special tool to
ASC-ECU.
(2) Ignition switch: ON
(3) Measure the voltage between the terminal No. 45
and the body earth.
OK: Battery voltage
Q: Is the check result normal?
YES : Go to Step 5.
NO : Go to Step 4.
35C-48
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 4. Connector check: A-05 ASC-ECU
connector
Connector: A-05
Main
STEP 5. Measure the resistance at A-05 ASC-ECU
Index
connector.
Connector: A-05
Group
TOC
A-05(Black)
A-05(Black)
Harness side
Harness side
AC601083 AB
AC601083 AB
Q: Is the check result normal?
YES : The open or short circuit may be present in
the power supply circuit to the motor. Repair
the harness wire between the ASC-ECU
connector terminal No. 45 and the fusible
link No. 3. Then go to Step 8.
NO : Repair the connector, and then go to Step 8.
MB991984
Check connector
ASC-ECU
ASC-ECU harness connector
AC601085AE
(1) Disconnect the connector, connect the ABS
check harness (Special tool: MB991984) to the
harness-side connector, and measure the voltage
at the special tool connector side.
NOTE: Do not connect the special tool to
ASC-ECU.
(2) Measure the resistance between terminal No. 46
and the body earth.
OK: Continuity exists (2 Ω or less)
Q: Is the check result normal?
YES : Go to Step 7.
NO : Go to Step 6.
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 6. Connector check: A-05 ASC-ECU
connector
Connector: A-05
35C-49
Main
STEP 8. ABS warning lamp OFF recheck
Drive the vehicle until the vehicle speed reaches 40 Index
km/h and check that the ABS warning lamp goes out.
Q: Does the ABS warning lamp extinguish?
YES : Go to Step 9.
NO : Return to Step 1.
A-05(Black)
Harness side
AC601083 AB
Q: Is the check result normal?
YES : An open circuit may be present in the earth
circuit. Repair the wiring harness between
the A-05 ASC-ECU terminal No. 46 and the
body earth. Then go to Step 8.
NO : Repair the connector, and then go to Step 8.
STEP 7. ABS warning lamp OFF recheck
Drive the vehicle until the vehicle speed reaches 40
km/h and check that the ABS warning lamp goes out.
Q: Does the ABS warning lamp extinguish?
YES : Go to Step 9.
NO : Replace the ASC-ECU, and then go to Step
8.
STEP 9. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is the diagnosis code No. C1266, C1273 or C1274
set?
YES : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : This diagnosis is complete.
Group
TOC
35C-50
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Main
Index
Code No. C1276: Valve relay system
Hydraulic unit (Motor and Solenoid Valve) Circuit
FUSIBLE
LINK 5
FUSIBLE
LINK 3
HYDRAULIC UNIT
MOTOR
SOLENOID
VALVE
POWER
SOURCE
ABS SOLENOID VALVE
MOTOR
POWER
SOURCE
ASC-ECU
Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
• ASC-ECU contains the power supply circuit (terminal No. 44) for the solenoid valve. The solenoid
valve is energised by the valve relay, which is
incorporated in ASC-ECU.
• The valve relay, which is incorporated in
ASC-ECU, is always energising the solenoid
valve unless the initial check is in progress when
the ignition switch is turned on, or the recurrent
system check is in progress.
DIAGNOSIS CODE SET CONDITIONS
The ECU monitors the power supply voltage to the
solenoid valve. If the voltage is not within the predetermined value, the ECU sets this diagnosis code as
a failure in the valve relay circuit.
Group
TOC
35C-51
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
PROBABLE CAUSES
Main
Current trouble
• Damaged wiring harness and connectors
• ASC-ECU malfunction
Past trouble
• Carry out diagnosis with particular emphasis on
connector(s) or wiring harness between the
power supply circuit (terminal No. 44) to the
ASC-ECU solenoid valve or earth circuit (terminal
No. 46). For diagnosis procedures, refer to How
to treat past trouble (GROUP 00 − How to Use
Troubleshooting/Inspection Service Points
P.00-13).
STEP 4. Measure the resistance at A-05 ASC-ECU
Index
connector.
Connector: A-05
Group
TOC
A-05(Black)
Harness side
AC601083 AB
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1276 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. Connector check: A-05 ASC-ECU
connector
MB991984
Check connector
ASC-ECU
ASC-ECU harness connector
AC601085AF
(1) Disconnect the connector, connect the ABS
check harness (Special tool: MB991984) to the
harness-side connector, and measure the voltage
at the special tool connector side.
NOTE: Do not connect the special tool to
ASC-ECU.
(2) Measure the resistance between the terminal No.
44 and the positive battery terminal.
OK: Continuity exists (2 Ω or less)
Connector: A-05
A-05(Black)
Harness side
AC601083 AB
Q: Is the check result normal?
YES : Go to Step 4.
NO : Repair the damaged connector.
Q: Is the check result normal?
YES : Go to Step 5.
NO : Repair the wiring harness between the
terminal No. 44 and the positive battery
terminal.
35C-52
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 5. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is the diagnosis code No. C1276 set?
YES : . Replace the ASC-ECU.
NO : . Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
35C-53
Main
Index
Code No. C1278: Valve relay stuck OFF
Hydraulic unit (Motor and Solenoid Valve) Circuit
FUSIBLE
LINK 5
FUSIBLE
LINK 3
HYDRAULIC UNIT
MOTOR
SOLENOID
VALVE
POWER
SOURCE
ABS SOLENOID VALVE
MOTOR
POWER
SOURCE
ASC-ECU
Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
• ASC-ECU contains the power supply circuit (terminal No. 44) for the solenoid valve. The solenoid
valve is energised by the valve relay, which is
incorporated in ASC-ECU.
• The valve relay, which is incorporated in
ASC-ECU, is always energising the solenoid
valve unless the initial check is in progress when
the ignition switch is turned on, or the recurrent
system check is in progress.
DIAGNOSIS CODE SET CONDITIONS
When the solenoid valve is not energised even after
the valve relay is turned ON, the ECU determines
that the valve relay stuck OFF and sets this diagnosis code.
PROBABLE CAUSES
Current trouble
• Damaged wiring harness and connectors
• The ABS-ECU is defective.
Group
TOC
35C-54
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Past trouble
• Carry out diagnosis with particular emphasis on
connector(s) or wiring harness between the
power supply circuit (terminal No. 44) to the
ASC-ECU solenoid valve or earth circuit (terminal
No. 46). For diagnosis procedures, refer to How
to treat past trouble (GROUP 00 − How to Use
Troubleshooting/Inspection Service Points
P.00-13).
Main
STEP 4. Measure the resistance at A-05 ASC-ECU
Index
connector.
Connector: A-05
Group
TOC
A-05(Black)
Harness side
DIAGNOSTIC PROCEDURE
AC601083 AB
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1278 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. Connector check: A-05 ASC-ECU
connector
MB991984
Check connector
ASC-ECU
Connector: A-05
ASC-ECU harness connector
A-05(Black)
Harness side
AC601083 AB
Q: Is the check result normal?
YES : Go to Step 4.
NO : Repair the damaged connector.
AC601085AF
(1) Disconnect the connector, connect the ABS
check harness (Special tool: MB991984) to the
harness-side connector, and measure the voltage
at the special tool connector side.
NOTE: Do not connect the special tool to
ASC-ECU.
(2) Measure the resistance between the terminal No.
44 and the positive battery terminal.
OK: Continuity exists (2 Ω or less)
Q: Is the check result normal?
YES : Go to Step 5.
NO : Repair the wiring harness between the
terminal No. 44 and the positive battery
terminal.
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 5. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
35C-55
Q: Is the diagnosis code No. C1278 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
Code No. C1279: Valve relay stuck ON
Hydraulic unit (Motor and Solenoid Valve) Circuit
FUSIBLE
LINK 5
FUSIBLE
LINK 3
HYDRAULIC UNIT
MOTOR
SOLENOID
VALVE
POWER
SOURCE
ABS SOLENOID VALVE
MOTOR
POWER
SOURCE
ASC-ECU
Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
• ASC-ECU contains the power supply circuit (terminal No. 44) for the solenoid valve. The solenoid
valve is energised by the valve relay, which is
incorporated in ASC-ECU.
• The valve relay, which is incorporated in
ASC-ECU, is always energising the solenoid
valve unless the initial check is in progress when
the ignition switch is turned on, or the recurrent
system check is in progress.
Main
Index
Group
TOC
35C-56
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
DIAGNOSIS CODE SET CONDITIONS
ASC-ECU monitors the power supply voltage to the
solenoid valve. If the solenoid valve is still energised
even after the valve relay is turned OFF, the ECU
determines that the motor relay stuck OFF, and sets
this diagnosis code.
Current trouble
• Damaged wiring harness and connectors
• The ABS-ECU is defective.
Main
STEP 4. Measure the resistance at A-05 ASC-ECU
Index
connector.
Connector: A-05
Group
TOC
A-05(Black)
Harness side
DIAGNOSTIC PROCEDURE
AC601083 AB
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1279 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. Connector check: A-05 ASC-ECU
connector
MB991984
Check connector
ASC-ECU
Connector: A-05
ASC-ECU harness connector
A-05(Black)
Harness side
AC601083 AB
Q: Is the check result normal?
YES : Go to Step 4.
NO : Repair the damaged connector.
AC601085AF
(1) Disconnect the connector, connect the ABS
check harness (Special tool: MB991984) to the
harness-side connector, and measure the voltage
at the special tool connector side.
NOTE: Do not connect the special tool to
ASC-ECU.
(2) Measure the resistance between the terminal No.
44 and the positive battery terminal.
OK: Continuity exists (2 Ω or less)
Q: Is the check result normal?
YES : Go to Step 5.
NO : Repair the wiring harness between the
terminal No. 44 and the positive battery
terminal.
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
35C-57
Q: Is the diagnosis code No. C1279 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
STEP 5. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
00 − How to Cope with Intermittent
Malfunction P.00-13.)
Code No. C1340: Stop lamp switch signal error
Stop Lamp Switch Circuit
FUSIBLE
LINK 1
STOP
LAMP
SWITCH
ASC-ECU
Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
ASC-ECU determines that the brake is/is not applied
based on the signals from 2-system stop lamp switch
and pressure sensor (incorporated in ASC-ECU). If
the signals from 2-system stop lamp switch and pressure sensor (incorporated in hydraulic unit) are differ,
the ECU determines that the trouble occurs and sets
the diagnosis code.
Main
Index
Group
TOC
35C-58
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
DIAGNOSIS CODE SET CONDITIONS
If the signals from 2-system stop lamp switch and
pressure sensor (incorporated in hydraulic unit) are
differ, the ECU determines that the trouble occurs
and sets the diagnosis code.
Current trouble
• Damaged wiring harness and connectors
• Malfunction of the stop lamp switch
• ASC-ECU malfunction
STEP 5. Voltage measurement: A-05 ASC-ECU
connector
Connector: A-05
Group
TOC
A-05(Black)
Harness side
DIAGNOSTIC PROCEDURE
AC601083 AB
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Connector check: B-27 Stop lamp switch
connector
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the damaged connector.
STEP 3. Check of the stop lamp switch as single
unit
Refer to GROUP 35A − Stop Lamp Switch Continuity
P.35A-22.
Q: Is the check result normal?
YES : Go to Step 4.
NO : Replace the stop lamp switch.
STEP 4. Connector check: A-05 ASC-ECU
connector
Q: Is the check result normal?
YES : Go to Step 5.
NO : Repair the damaged connector.
Main
Index
MB991984
Check connector
ASC-ECU
ASC-ECU harness connector
AC601086AB
(1) Disconnect the connector, connect the ASC
check harness (Special tool: MB991984) to the
ABS-ECU side connector and harness-side
connector, and then measure the voltage at the
special tool connector side.
(2) Ignition switch: ON
(3) Measure the voltage between the terminal No. 6
and the body earth.
OK:
<When the brake pedal is not depressed>
2V or less
<When the brake pedal is depressed> 4.5V
or more
Q: Is the check result normal?
YES : Go to Step 6.
NO : Repair the wiring harness.
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 6. Measure the resistance at A-05 ASC-ECU
connector.
Connector: A-05
STEP 7. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
(4) Depress the brake pedal for 2 seconds or more.
Q: Is the diagnosis code No. C1340 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
A-05(Black)
Harness side
00 − How to Cope with Intermittent
Malfunction P.00-13.)
AC601083 AB
MB991984
35C-59
Check connector
ASC-ECU
ASC-ECU harness connector
AC601085AG
(1) Disconnect A-05 ASC-ECU connector, connect
the ABS check harness (Special tool: MB991984)
to the harness-side connector, and measure the
voltage at the special tool connector side.
NOTE: . Do not connect the special tool to
ASC-ECU.
(2) Measure the resistance between the terminal No.
23 and the body earth.
OK:
<When the brake pedal is not depressed>
Continuity (2V Ω or less)
<When the brake pedal is depressed> No
continuity
Q: Is the check result normal?
YES : . Go to Step 7.
NO : Repair the wiring harness.
Main
Index
Group
TOC
35C-60
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Main
Index
Code No. C1345: Low brake fluid level
Brake Fluid Level Switch Circuit
ASC-ECU
BRAKE
FLUID
LEVEL
SWITCH
(EARTH 7)
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
ASC-ECU monitors the brake fluid level by the brake
fluid level switch signal.
DIAGNOSIS CODE SET CONDITIONS
When the brake fluid level is lower than the specified
value, the brake fluid level switch is turned ON, the
ASC-ECU terminal No. 32 is grounded, and then the
ECU determines that the brake fluid level is low and
sets this diagnosis code.
Current trouble
• Damaged wiring harness and connectors
• Low brake fluid level
• Long-time cornering in a certain direction (The
brake fluid level is tilted by centrifugal force, and
the low brake fluid level may be detected temporarily.)
• Brake fluid level switch malfunction
• ASC-ECU malfunction
Wire colour code
B : Black LG : Light green
G : Green L : Blue
W : White Y : Yellow
SB : Sky blue BR : Brown
O : Orange GR : Grey
R : Red P : Pink
V : Violet PU : Purple
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP2: Brake fluid level check
Check whether the brake fluid level is within the
specified value.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Check the brake pad thickness and brake
fluid line leakage.
Group
TOC
35C-61
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 3. Connector check: A-05 ASC-ECU
connector, A-03 brake fluid level switch
connector
Main
Index
Connector: A-03
A-03(Grey)
Connector: A-05
Harness
side
A-05(Black)
AC601084 AC
Harness side
AC601083 AB
Connector: A-03
A-03(Grey)
Harness
side
AC601084 AC
Q: Is the check result normal?
YES : Go to Step 4.
NO : Repair the damaged connector.
STEP 4. Resistance measurement: between A-05
ASC-ECU connector and A-03 brake fluid level
switch connector
Connector: A-05
A-05(Black)
Harness side
AC601083 AB
MB991984
Check connector
ASC-ECU
ASC-ECU harness connector
AC601085AH
(1) Disconnect A-05 ASC-ECU connector and A-03
brake fluid level switch connector, and connect
the ABS check harness (Special tool: MB991984)
to the harness side connector.
NOTE: Do not connect the special tool to
ASC-ECU.
(2) Resistance between the ABS check harness
(Special tool: MB991984) connector terminal No.
32 and body earth
OK: No continuity
Q: Is the check result normal?
YES : Go to Step 6.
NO : Go to Step 5.
STEP 5. Brake fluid level sensor check
Refer to GROUP 35A − Brake fluid level sensor
check P.35A-11.
Q: Is the check result normal?
YES : Go to Step 6.
NO : Replace the brake fluid level sensor.
Group
TOC
35C-62
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 6. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is the diagnosis code No. C1345 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
Code No. C1364: Internal malfunction of pressure sensor
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
ASC-ECU incorporates the pressure sensor, and
monitors the brake fluid pressure.
DIAGNOSIS CODE SET CONDITIONS
This diagnostic trouble codes will be set under the
cases below:
• Pressure sensor power supply voltage malfunction
• Pressure sensor signal malfunction
• Abnormal result of initial check performed when
the power is supplied to ASC-ECU.
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Replace the ASC-ECU.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1364 set?
YES : Replace the ASC-ECU.
NO : This diagnosis is complete.
Current trouble
• ASC-ECU malfunction
Code No. C1366: Lateral G-sensor signal error
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
The G and yaw rate sensor output signal is sent to
ASC-ECU via the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
ASC-ECU monitors the G and yaw rate sensor output signal, and when an abnormality is present in the
signal from the G and yaw rate sensor, the ECU
determines that the trouble occurs and sets the diagnosis code.
Current trouble
• G and yaw rate sensor malfunction
• G and yaw rate sensor improper installation
• Driving under special conditions (bad road, etc.)
• ASC-ECU malfunction
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1366 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 3. G and yaw rate sensor installation state
check
Check that the G and yaw rate sensor is installed
correctly.
Q: Is the check result normal?
YES : Go to Step 4.
NO : Reinstall the G and yaw rate sensor
correctly.
STEP 4. M.U.T.-III data list
Check the following service data. (Refer to
P.35C-109.)
• Item No. 14: Lateral G-sensor
Q: Is the check result normal?
YES : Go to Step 5.
NO : Replace the G and yaw rate sensor, and
then go to Step 6.
35C-63
STEP 5. Diagnosis code recheck
(1) Ignition switch: ON
(2) Erase the diagnosis code.
(3) Ignition switch: LOCK (OFF) position
(4) Start the engine.
(5) Drive the vehicle at 40 km/h or more.
Q: Is the diagnosis code No. C1366 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
STEP 6. Diagnosis code recheck
(1) Ignition switch: ON
(2) Erase the diagnosis code.
(3) Ignition switch: LOCK (OFF) position
(4) Start the engine.
(5) Drive the vehicle at 40 km/h or more.
Q: Is the diagnosis code No. C1366 set?
YES : Replace the ASC-ECU.
NO : This diagnosis is complete.
Code No. C1371: Yaw rate sensor signal error
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
The G and yaw rate sensor output signal is sent to
ASC-ECU via the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
ASC-ECU monitors the G and yaw rate sensor output signal, and when an abnormality is present in the
signal from the G and yaw rate sensor, the ECU
determines that the trouble occurs and sets the diagnosis code.
Current trouble
• G and yaw rate sensor malfunction
• G and yaw rate sensor improper installation
• Driving under special conditions (bad road, etc.)
• ASC-ECU malfunction
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1371 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. G and yaw rate sensor installation state
check
Check that the G and yaw rate sensor is installed
correctly (not tilted).
Q: Is the check result normal?
YES : Go to Step 4.
NO : Reinstall the G and yaw rate sensor
correctly.
Main
Index
Group
TOC
35C-64
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 4. M.U.T.-III data list
Check the following service data.(Refer to
P.35C-109.)
• Item No.17: Yaw rate sensor
Q: Is the check result normal?
YES : Go to Step 5.
NO : Replace the G and yaw rate sensor, and
then go to Step 6.
STEP 5. Diagnosis code recheck
(1) Ignition switch: ON
(2) Erase the diagnosis code.
(3) Ignition switch: LOCK (OFF) position
(4) Start the engine.
(5) Drive the vehicle at 40 km/h or more.
Q: Is the diagnosis code No. C1371 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
STEP 6. Diagnosis code recheck
(1) Ignition switch: ON
(2) Erase the diagnosis code.
(3) Ignition switch: LOCK (OFF) position
(4) Start the engine.
(5) Drive the vehicle at 40 km/h or more.
Q: Is the diagnosis code No. C1371 set?
YES : Replace the ASC-ECU.
NO : This diagnosis is complete.
Code No. C1385: Yaw rate sensor error
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
The G and yaw rate sensor output signal is sent to
ASC-ECU via the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
If an abnormality is judged to have occurred in the G
and yaw rate sensor, the G and yaw rate sensor
sends a diagnostic signal to ASC-ECU. When
ASC-ECU receives this diagnostic signal, it determines that the sensor has a trouble and sets the
diagnosis code.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1385 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. G and yaw rate sensor installation state
check
Check that the G and yaw rate sensor is installed
correctly (not tilted).
Q: Is the check result normal?
YES : Go to Step 4.
NO : Reinstall the G and yaw rate sensor
correctly.
Current trouble
• G and yaw rate sensor malfunction
• Driving under special conditions (bad road, etc.)
• ASC-ECU malfunction
STEP 4. M.U.T.-III data list
Check the following service data.(Refer to
P.35C-109.)
• Item No.17: Yaw rate sensor
DIAGNOSTIC PROCEDURE
Q: Is the check result normal?
YES : Go to Step 5.
NO : Replace the G and yaw rate sensor, and
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
then go to Step 6.
STEP 5. Diagnosis code recheck
(1) Ignition switch: ON
(2) Erase the diagnosis code.
(3) Ignition switch: LOCK (OFF) position
(4) Start the engine.
(5) Drive the vehicle at 40 km/h or more.
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Q: Is the diagnosis code No. C1385 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
35C-65
STEP 6. Diagnosis code recheck
(1) Ignition switch: ON
(2) Erase the diagnosis code.
(3) Ignition switch: LOCK (OFF) position
(4) Start the engine.
(5) Drive the vehicle at 40 km/h or more.
Q: Is the diagnosis code No. C1385 set?
YES : Replace the ASC-ECU.
NO : This diagnosis is complete.
Code No. C1387: Lateral G-sensor error
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
The G and yaw rate sensor output signal is sent to
ASC-ECU via the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
If an abnormality is judged to have occurred in the G
and yaw rate sensor, the G and yaw rate sensor
sends a diagnostic signal to ASC-ECU. When
ASC-ECU receives this diagnostic signal, it determines that the sensor has a trouble and sets the
diagnosis code.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1387 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. G and yaw rate sensor installation state
check
Check that the G and yaw rate sensor is installed
correctly (not tilted).
Q: Is the check result normal?
YES : Go to Step 4.
NO : Reinstall the G and yaw rate sensor
correctly.
Current trouble
• G and yaw rate sensor malfunction
• Driving under special conditions (bad road, etc.)
• ASC-ECU malfunction
STEP 4. M.U.T.-III data list
Check the following service data.(Refer to
P.35C-109.)
• Item No. 14: Lateral G-sensor
DIAGNOSTIC PROCEDURE
Q: Is the check result normal?
YES : Go to Step 5.
NO : Replace the G and yaw rate sensor, and
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
then go to Step 6.
STEP 5. Diagnosis code recheck
(1) Ignition switch: ON
(2) Erase the diagnosis code.
(3) Ignition switch: LOCK (OFF) position
(4) Start the engine.
(5) Drive the vehicle at 40 km/h or more.
Q: Is the diagnosis code No. C1387 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
Main
Index
Group
TOC
35C-66
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 6. Diagnosis code recheck
(1) Ignition switch: ON
(2) Erase the diagnosis code.
(3) Ignition switch: LOCK (OFF) position
(4) Start the engine.
(5) Drive the vehicle at 40 km/h or more.
Q: Is the diagnosis code No. C1387 set?
YES : Replace the ASC-ECU.
NO : This diagnosis is complete.
Code No. C1388: Yaw rate sensor active check error
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
The G and yaw rate sensor output signal is sent to
ASC-ECU via the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
ASC-ECU monitors the G and yaw rate sensor output signal, and when an abnormality is present in the
signal from the G and yaw rate sensor, the ECU
determines that the trouble occurs and sets the diagnosis code.
Current trouble
• G and yaw rate sensor malfunction
• ASC-ECU malfunction
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1371 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. M.U.T.-III data list
Check the following service data.(Refer to
P.35C-109.)
• Item No.17: Yaw rate sensor
Q: Is the check result normal?
YES : Go to Step 4.
NO : Replace the G and yaw rate sensor, and
then go to Step 5.
STEP 4. Diagnosis code recheck
(1) Ignition switch: ON
(2) Erase the diagnosis code.
(3) Ignition switch: LOCK (OFF) position
(4) Start the engine.
(5) Drive the vehicle at 40 km/h or more.
Q: Is the diagnosis code No. C1388 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
STEP 5. Diagnosis code recheck
(1) Ignition switch: ON
(2) Erase the diagnosis code.
(3) Ignition switch: LOCK (OFF) position
(4) Start the engine.
(5) Drive the vehicle at 40 km/h or more.
Q: Is the diagnosis code No. C1388 set?
YES : Replace the ASC-ECU.
NO : This diagnosis is complete.
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
35C-67
Code No. C1394: Steering wheel sensor neutral point not learned
OPERATION
The steering wheel sensor output signal is sent to
ASC-ECU via the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
ASC-ECU receives the information of the steering
wheel sensor calibration from the steering wheel
sensor. When this information indicates that the calibration is not performed, the ECU sets the diagnosis
code.
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III data list
Check the following service data.(Refer to
P.35C-109.)
• Item No. 30: SAS calibration flag
Q: Is the check result normal?
YES : Go to Step 2.
NO : Perform calibration of steering wheel
sensor.(Refer to P.35C-119.) Then go to
Step 2.
PROBABLE CAUSES
• Steering wheel sensor calibration not implemented
• ASC-ECU malfunction
STEP 2. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is the diagnosis code No. C1394 set?
YES : Replace the ASC-ECU.
NO : This diagnosis is complete.
Code No. C1396: Engine torque intervention rejection
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
ASC-ECU receives the engine system-related signal
from the engine ECU via CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
When the torque request rejection signal from the
engine ECU indicates the rejection state, ASC-ECU
determines that the trouble occurs and sets this diagnosis code.
Current trouble
• Engine ECU malfunction
• ASC-ECU malfunction
Main
Index
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1396 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. M.U.T.-III diagnosis code for other
systems
Check that the engine ECU sets a diagnosis code.
Q: Is the diagnosis code set?
YES : Go to Step 4.
NO : Troubleshoot the engine-ECU. (Refer to
GROUP 13B − Troubleshooting P.13B-18.)
Group
TOC
35C-68
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 4. M.U.T.-III diagnosis code
Check if the diagnosis code other than the code No.
C1396 is set from ASC-ECU.
Q: Is the diagnosis code other than the code No.
C1396 set?
YES : Troubleshoot for the relevant diagnosis
code. (Refer to P.35C-6.)
NO : Replace the engine ECU. Then go to Step
5.
STEP 5. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is the diagnosis code No. C1396 set?
YES : Replace the ASC-ECU.
NO : This diagnosis is complete.
Code No. C1505: Steering wheel sensor error
OPERATION
The steering wheel sensor output signal is sent to
ASC-ECU via the dedicated CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
ASC-ECU monitors the signal from the steering
wheel sensor, when an abnormal signal is output
from the steering wheel sensor, the ECU determines
that the trouble occurs and sets the diagnosis code.
PROBABLE CAUSES
•
•
•
•
Steering wheel sensor malfunction
Steering wheel sensor improper installation
Steering wheel sensor calibration error
ASC-ECU malfunction
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III data list
With the front wheel facing in the straight-ahead
direction, check the steering wheel sensor signal
using the data list. Check that the data list shows the
deviation within ±5° from the neutral position.(Refer
to P.35C-109.)
• Item No. 16: Steering angle sensor
Q: Is the check result normal?
YES : Go to Step 2.
NO : Perform calibration of steering wheel
sensor.(Refer to P.35C-119.)
STEP 2. Steering wheel sensor installation state
check
Check that the steering wheel sensor is installed correctly.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Install the steering wheel sensor correctly.
STEP 3. M.U.T.-III data list
Turn the steering wheel fully to the left, and then turn
it fully to the right. Then check that the value of the
steering wheel sensor changes smoothly using the
data list. In addition, check that the steering wheel
angle on the data list almost matches the actual
steering wheel angle.(Refer to P.35C-109.)
• Item No. 16: Steering angle sensor
Q: Is the check result normal?
YES : Go to Step 4.
NO : After the steering wheel is replaced, perform
the steering wheel sensor calibration.(Refer
to P.35C-119.)
STEP 4. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is diagnosis code No. C1505 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
35C-69
Code No. C1555: Steering wheel sensor exceeding the normal range
OPERATION
The steering wheel sensor output signal is sent to
ASC-ECU via the dedicated CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
STEP 2. Steering wheel sensor installation state
Group
check
Check that the steering wheel sensor is installed cor- TOC
rectly.
When an abnormality (larger than the actual maximum steering angle) is detected in the steering
angle, the diagnosis is set.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Install the steering wheel sensor correctly.
PROBABLE CAUSES
STEP 3. M.U.T.-III data list
Turn the steering wheel fully to the left, and then turn
it fully to the right. Then check that the value of the
steering wheel sensor changes smoothly using the
data list. In addition, check that the steering wheel
angle on the data list almost matches the actual
steering wheel angle.(Refer to P.35C-109.)
• Item No. 16: Steering angle sensor
•
•
•
•
Steering wheel sensor malfunction
Steering wheel sensor improper installation
Steering wheel sensor calibration error
ASC-ECU malfunction
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III data list
With the front wheel facing in the straight-ahead
direction, check the steering wheel sensor signal
using the data list. Check that the data list shows the
deviation within ±5° from the neutral position.(Refer
to P.35C-109.)
• Item No. 16: Steering angle sensor
Q: Is the check result normal?
YES : Go to Step 2.
NO : Perform calibration of steering wheel
sensor.(Refer to P.35C-119.)
Q: Is the check result normal?
YES : Go to Step 4.
NO : After the steering wheel is replaced, perform
the steering wheel sensor calibration.(Refer
to P.35C-119.)
STEP 4. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is diagnosis code No. C1505 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
Code No. C1607: Malfunction of ASC-ECU
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
When an abnormality is present in the internal
ASC-ECU, this diagnosis code is set.
PROBABLE CAUSES
ASC-ECU malfunction
Main
Index
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 2.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
35C-70
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 2. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is the diagnosis code No. C1607 set?
YES : Replace the ASC-ECU.
NO : This diagnosis is complete.
Code No. C1621: G and yaw rate sensor improper installation
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
OPERATION
ASC-ECU automatically recognises the type of G
and yaw rate sensor via the CAN bus lines. If another
type of G and yaw rate sensor is installed after automatic recognition, this code is stored.
DIAGNOSIS CODE SET CONDITIONS
If an abnormality is judged to have occurred in the G
and yaw rate sensor, the G and yaw rate sensor
sends a diagnostic signal to ASC-ECU. When
ASC-ECU receives this diagnostic signal, it determines that the sensor has a trouble and sets the
diagnosis code.
Current trouble
• Another type G and yaw rate sensor installation
• ASC-ECU malfunction
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1621 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. Diagnosis code recheck
Check if the diagnosis code No. C1621 is set as a
past trouble.
Q: Is the trouble set as a past trouble?
YES : Erase the diagnosis code No. C1621.
NO : Go to Step 4.
STEP 4. Diagnosis code recheck after sensor ID
erase execution
(1) Erase the sensor ID.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
(4) Erase the diagnosis code.
Q: Is the diagnosis code No. C1621 set?
YES : Replace the G and yaw rate sensor, and
then go to Step 5.
NO : This diagnosis is complete.
STEP 5. Diagnosis code recheck after sensor ID
erase execution
(1) Erase the sensor ID.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
(4) Erase the diagnosis code.
Q: Is the diagnosis code No. C1621 set?
YES : Replace the ASC-ECU, and then go to Step
6.
NO : This diagnosis is complete.
STEP 6. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is the diagnosis code No. C1621 set?
YES : Return to Step 1.
NO : This diagnosis is complete.
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
35C-71
Code No. C1860: Abnormal rise of ASC-ECU power supply voltage
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
ASC-ECU monitors the ASC-ECU power supply voltage sent from the battery. When the voltage rises up
to approximately 17 V or more, the ECU determines
that the trouble occurs and sets the diagnosis code.
Current trouble
• Charging circuit failure
• ASC-ECU malfunction
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1860 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. Battery terminal voltage measurement
(1) Start the engine.
(2) Set the engine speed to approximately 2500 rpm.
(3) Measure the voltage between the positive and
negative battery terminals.
OK: 16 V or less
Q: Is the check result normal?
YES : Go to Step 4.
NO : Diagnose the charging system. (Refer to
GROUP 16 − On-vehicle Service P.16-6.)
STEP 4. Diagnosis code recheck
(1) Start the engine.
(2) Set the engine speed to approximately 2500 rpm.
Q: Is the diagnosis code No. C1860 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
Main
Index
Group
TOC
35C-72
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Code No. C1861: Abnormal drop of ASC-ECU power supply voltage
Hydraulic unit (Motor and Solenoid Valve) Circuit
FUSIBLE
LINK 5
FUSIBLE
LINK 3
HYDRAULIC UNIT
MOTOR
SOLENOID
VALVE
POWER
SOURCE
ABS SOLENOID VALVE
MOTOR
POWER
SOURCE
ASC-ECU
Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
ASC-ECU monitors the ASC-ECU power supply voltage sent from the battery. When the voltage is
approximately 8 V or less at the vehicle speed of 6
km/h, the ECU determines that the trouble occurs
and sets the diagnosis code.
Current trouble
• Damaged wiring harness and connectors
• Charging circuit failure
• ASC-ECU malfunction
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
Main
Index
Group
TOC
35C-73
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1861 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. Battery terminal voltage measurement
(1) Start the engine.
(2) Measure the voltage between the positive and
negative battery terminals.
OK: 10 V or more
STEP 5. Voltage measurement: A-05 ASC-ECU
connector
Main
Index
Connector: A-05
Group
TOC
A-05(Black)
Harness side
AC601083 AB
Q: Is the check result normal?
YES : Go to Step 4.
NO : Diagnose the charging system. (Refer to
GROUP 16 − On-vehicle Service P.16-6.)
STEP 4. Connector check: A-05 ASC-ECU
connector
Connector: A-05
A-05(Black)
Harness side
MB991984
AC601083 AB
Check connector
ASC-ECU
Q: Is the check result normal?
YES : Go to Step 5.
NO : Repair the damaged connector.
ASC-ECU harness connector
AC601086AC
(1) Disconnect the connector, connect the ASC
check harness (Special tool: MB991984) to the
ASC-ECU side connector and harness-side
connector, and then measure the voltage at the
special tool connector side.
(2) Start the engine.
(3) Measure the voltage between the terminal No. 40
and the body earth.
OK: 10 V or more
Q: Is the check result normal?
YES : Go to Step 6.
NO : Repair the wiring harness.
35C-74
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 6. Measure the resistance at A-05 ASC-ECU
connector.
Connector: A-05
Q: Is the diagnosis code No. C1861 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
A-05(Black)
Harness side
00 − How to Cope with Intermittent
Malfunction P.00-13.)
AC601083 AB
MB991984
STEP 7. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Start the engine.
(4) Drive the vehicle at 6 km/h or more.
Check connector
ASC-ECU
ASC-ECU harness connector
AC601085AI
(1) Disconnect the connector, connect the ASC
check harness (Special tool: MB991984) to the
harness-side connector, and measure the voltage
at the special tool connector side.
NOTE: . Do not connect the special tool to
ASC-ECU.
(2) Measure the resistance between the terminal No.
43 and the body earth.
OK: Continuity exists (2 Ω or less)
Q: Is the check result normal?
YES : . Go to Step 7.
NO : . Repair the wiring harness.
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
35C-75
Code No. C1862: Abnormal power supply voltage of G and yaw rate sensor (high voltage)
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
The G and yaw rate sensor monitors the G and yaw
rate sensor power supply voltage supplied from the
battery. When the voltage rises up to approximately
17 V or more, the sensor determines that the trouble
occurs and sets the diagnosis code.
Current trouble
• Charging circuit failure
• G and yaw rate sensor malfunction
DIAGNOSTIC PROCEDURE
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1862 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. Battery terminal voltage measurement
(1) Start the engine.
(2) Set the engine speed to approximately 2500 rpm.
(3) Measure the voltage between the positive and
negative battery terminals.
OK: 16 V or less
Q: Is the check result normal?
YES : Go to Step 4.
NO : Diagnose the charging system. (Refer to
GROUP 16 − On-vehicle Service P.16-6.)
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 4. Diagnosis code recheck
(1) Start the engine.
(2) Set the engine speed to approximately 2500 rpm.
Q: Is the diagnosis code No. C1862 set?
YES : Replace the G and yaw rate sensor.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
Main
Index
Group
TOC
35C-76
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Code No. C1863: Abnormal power supply voltage of G and yaw rate sensor (low voltage)
G and Yaw Rate Sensor Power Source Circuit
G AND
YAW RATE
SENSOR
Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
The G and yaw rate sensor monitors the G and yaw
rate sensor power supply voltage supplied from the
battery. When the voltage drops to approximately 8 V
or less, the sensor determines that the trouble occurs
and sets the diagnosis code.
Current trouble
• Damaged wiring harness and connectors
• Charging circuit failure
• G and yaw rate sensor malfunction
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. C1863 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
Main
Index
Group
TOC
35C-77
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 3. Battery terminal voltage measurement
(1) Start the engine.
(2) Measure the voltage between the positive and
negative battery terminals.
OK: 10 V or more
Q: Is the check result normal?
YES : Go to Step 4.
NO : Diagnose the charging system. (Refer to
STEP 5. Connector check: C-45 G and yaw rate
sensor connector, B-110 junction block
connector
Group
TOC
Connector: C-45
Harness side
GROUP 16 − On-vehicle Service P.16-6.)
STEP 4. Measure the voltage at C-45 G and yaw
rate sensor connector.
C-45(Black)
AC601093 AC
Connector: C-45
Connector: B-110
J/B
(Front
i ‡ view)
û
j
Harness side
Harness side
C-45(Black)
AC601093 AC
AC601106 AB
Connector: C-45
Q: Is the check result normal?
YES : Go to Step 6.
NO : Repair the damaged connector.
Harness side
AC601339 AD
(1) Disconnect C-45 G and yaw rate sensor
connector, and measure at the harness side.
(2) Measure the voltage between the terminal No. 1
and the body earth.
OK: 9 V or more
Q: Is the check result normal?
YES : . Go to Step 7.
NO : . Go to Step 5.
Main
Index
35C-78
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 6. Check the harness wire between C-45 G
and yaw rate sensor connector and B-110
junction block connector.
STEP 7. Measure the resistance at C-45 G and
yaw rate sensor connector.
Connector: C-45
Group
TOC
Connector: C-45
Harness side
Harness side
C-45(Black)
C-45(Black)
AC601093 AC
AC601093 AC
Connector: C-45
Connector: B-110
J/B
(Front
i ‡ view)
û
j
Harness side
Harness side
AC601339 AE
AC601106 AB
Q: Is the check result normal?
YES : Go to Step 7.
NO : Repair the wiring harness.
Main
Index
(1) Disconnect C-45 G and yaw rate sensor
connector, and measure at the harness side.
(2) Measure the resistance between the terminal No.
4 and the body earth.
OK: Continuity exists (2 Ω or less)
Q: Is the check result normal?
YES : Go to Step 8.
NO : Repair the wiring harness.
STEP 8. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is the diagnosis code No. C1863 set?
YES : Replace the G and yaw rate sensor.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
35C-79
Main
Index
Code No. U1073: Bus-off
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
When ASC-ECU has ceased the CAN communication (bus-off), the diagnosis code No. U1073 is
stored. The communication is resumed when the
ignition switch is tuned to the "LOCK" (OFF) position
and then to ON position again.
DIAGNOSTIC PROCEDURE
M.U.T.-III CAN bus diagnosis
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.)
Probable causes
• Damaged wiring harness and connectors
Code No. U1100: Engine-related CAN time-out error
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
ASC-ECU receives the engine control system-related signals from the engine ECU via the
CAN bus lines. When these signals cannot be
received, the ECU stores the diagnosis code No.
U1100.
COMMENTS ON TROUBLE SYMPTOM
Current trouble
• Connector(s) or wiring harness in the CAN bus
lines between the ASC-ECU and the
engine-ECU, the power supply system to the
engine-ECU, or the ASC-ECU itself may be
defective.
Past trouble
• If diagnosis code No. U1100 is stored as a past
trouble, carry out diagnosis with particular
emphasis on connector(s) and wiring harness in
the CAN bus line between the ASC-ECU and the
engine ECU, and the power supply system to
ASC-ECU. For diagnosis procedures, refer to
How to treat past trouble (refer to GROUP 00,
How to Use Troubleshooting/Inspection Service
Points P.00-13).
NOTE: For a past trouble, you can not find it by the
M.U.T.-III CAN bus diagnostics even if there is
any failure in CAN bus lines. In this case, refer to
GROUP 00 − How to Use Troubleshooting/Inspection Service Points P.00-13 and check
the CAN bus lines. You can narrow down the
possible cause of the trouble by referring to the
diagnosis code, which is set regarding the CAN
communication-linked ECUs (Refer to GROUP
54D − CAN Bus Line Diagnostic Flow P.54D-7).
Probable causes
• Engine ECU malfunction
• ASC-ECU malfunction
• Damaged wiring harness and connectors
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. U1100 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
Group
TOC
35C-80
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 3. M.U.T.-III diagnosis code for other
systems
Use M.U.T.-III to check that other diagnosis code is
set in the ECU corresponding to the relevant diagnosis code.
STEP 4. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is other diagnosis code set?
YES : Troubleshoot for the relevant diagnosis
Q: Is the diagnosis code No. U1100 set?
YES : Replace the ASC-ECU.
NO : This diagnosis is complete.
code.
NO : Replace the engine ECU. Then go to Step
4.
Code No. U1104: Steering wheel sensor CAN time-out error
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
ASC-ECU receives the steering angle-related signals from the steering wheel sensor via the CAN bus
lines. When these signals cannot be received, the
diagnosis code No. U1104 is stored.
COMMENTS ON TROUBLE SYMPTOM
Current trouble
• The connector(s) or wiring harness in the CAN
bus line between ASC-ECU and the steering
wheel sensor may be damaged, or the steering
wheel sensor power supply circuit or ASC-ECU
may be faulty.
Past trouble
• If diagnosis code No. U1104 is stored as a past
trouble, carry out diagnosis with particular
emphasis on connector(s) and wiring harness in
the CAN bus line between the ASC-ECU and the
steering wheel sensor, and the steering wheel
sensor power supply circuit. For diagnosis procedures, refer to How to treat past trouble (refer to
GROUP 00, How to Use Troubleshooting/Inspection Service Points P.00-13).
NOTE: For a past trouble, you can not find it by the
M.U.T.-III CAN bus diagnostics even if there is
any failure in CAN bus lines. In this case, refer to
GROUP 00 − How to Use Troubleshooting/Inspection Service Points P.00-13 and check
the CAN bus lines. You can narrow down the
possible cause of the trouble by referring to the
diagnosis code, which is set regarding the CAN
communication-linked ECUs. (Refer to GROUP
54D − CAN Bus Line Diagnostic Flow P.54D-7.)
Probable causes
• Steering wheel sensor malfunction
• ASC-ECU malfunction
• Damaged wiring harness and connectors
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. U1104 set?
YES : Replace the steering wheel sensor.(Refer to
P.35C-125.) Then go to Step 3.
NO : This diagnosis is complete.
STEP 3. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is the diagnosis code No. U1104 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
35C-81
Main
Index
Code No. U1105: G and yaw rate sensor CAN time-out error
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
ASC-ECU receives the steering angle-related signals from the G and yaw rate sensor via the CAN bus
lines. When these signals cannot be received, the
diagnosis code No. U1105 is stored.
COMMENTS ON TROUBLE SYMPTOM
Current trouble
• The connector(s) or wiring harness in the CAN
bus line between ASC-ECU and the G and yaw
rate sensor may be damaged, or the G and yaw
rate sensor power supply circuit or ASC-ECU
may be faulty.
Past trouble
• If diagnosis code No. U1105 is stored as a past
trouble, carry out diagnosis with particular
emphasis on connector(s) and wiring harness in
the CAN bus line between the ASC-ECU and the
G and yaw rate sensor, and the G and yaw rate
sensor power supply circuit. For diagnosis procedures, refer to How to treat past trouble (refer to
GROUP 00, How to Use Troubleshooting/Inspection Service Points P.00-13).
NOTE: For a past trouble, you can not find it by the
M.U.T.-III CAN bus diagnostics even if there is
any failure in CAN bus lines. In this case, refer to
GROUP 00 − How to Use Troubleshooting/Inspection Service Points P.00-13 and check
the CAN bus lines. You can narrow down the
possible cause of the trouble by referring to the
diagnosis code, which is set regarding the CAN
communication-linked ECUs. (Refer to GROUP
54D − CAN Bus Line Diagnostic Flow P.54D-7.)
Probable causes
• G and yaw rate sensor malfunction
• ASC-ECU malfunction
• Damaged wiring harness and connectors
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. U1105 set?
YES : Replace the G and yaw rate sensor, and
then go to Step 3.
NO : This diagnosis is complete.
STEP 3. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is the diagnosis code No. U1105 set?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
Group
TOC
35C-82
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Main
Index
Code No. U1406: Acceleration pedal position signal error
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
ASC-ECU receives the engine control system-related signals from the engine ECU via the
CAN bus lines. When the information on trouble is
included in these signals, this diagnosis code is
stored.
COMMENTS ON TROUBLE SYMPTOM
Current trouble
• Connector(s) or wiring harness in the CAN bus
lines between the ASC-ECU and the
engine-ECU, the power supply system to the
engine-ECU, or the ASC-ECU itself may be
defective.
Past trouble
• If diagnosis code No. U1406 is stored as a past
trouble, carry out diagnosis with particular
emphasis on wiring and connector(s) in the CAN
bus line between the ASC-ECU and the
engine-ECU, and the power supply system to the
engine-ECU. For diagnosis procedures, refer to
How to treat past trouble (refer to GROUP 00,
How to Use Troubleshooting/Inspection Service
Points P.00-13).
NOTE: For a past trouble, you can not find it by the
M.U.T.-III CAN bus diagnostics even if there is
any failure in CAN bus lines. In this case, refer to
GROUP 00 − How to Use Troubleshooting/Inspection Service Points P.00-13 and check
the CAN bus lines. You can narrow down the
possible cause of the trouble by referring to the
diagnosis code, which is set regarding the CAN
communication-linked ECUs. (Refer to GROUP
54D − CAN Bus Line Diagnostic Flow P.54D-7.)
Probable causes
• Engine ECU malfunction
• ASC-ECU malfunction
• Damaged wiring harness and connectors
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. U0406 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. M.U.T.-III diagnosis code for other
systems
Use M.U.T.-III to check that the diagnosis code is set
in the other systems.
Q: Is the diagnosis code set?
YES : Troubleshoot for the relevant diagnosis
code.
NO : Replace the engine ECU, and then go to
Step 4.
STEP 4. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is the diagnosis code No. U0406 set?
YES : Replace the ASC-ECU.
NO : This diagnosis is complete.
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
35C-83
Main
Index
Code No. U1426: Engine speed signal error
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
ASC-ECU receives the engine speed-related signals
from the engine ECU via the CAN bus lines. When
the information on trouble is included in these signals, this diagnosis code is stored.
COMMENTS ON TROUBLE SYMPTOM
Current trouble
• Connector(s) or wiring harness in the CAN bus
lines between the ASC-ECU and the
engine-ECU, the power supply system to the
engine-ECU, or the ASC-ECU itself may be
defective.
Past trouble
• If diagnosis code No. U1426 is stored as a past
trouble, carry out diagnosis with particular
emphasis on wiring and connector(s) in the CAN
bus line between the ASC-ECU and the
engine-ECU, and the power supply system to the
engine-ECU. For diagnosis procedures, refer to
How to treat past trouble (refer to GROUP 00,
How to Use Troubleshooting/Inspection Service
Points P.00-13).
NOTE: For a past trouble, you can not find it by the
M.U.T.-III CAN bus diagnostics even if there is
any failure in CAN bus lines. In this case, refer to
GROUP 00 − How to Use Troubleshooting/Inspection Service Points P.00-13 and check
the CAN bus lines. You can narrow down the
possible cause of the trouble by referring to the
diagnosis code, which is set regarding the CAN
communication-linked ECUs. (Refer to GROUP
54D − CAN Bus Line Diagnostic Flow P.54D-7.)
Probable causes
• Engine ECU malfunction
• ASC-ECU malfunction
• Damaged wiring harness and connectors
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. U1426 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. M.U.T.-III diagnosis code for other
systems
Use M.U.T.-III to check that the diagnosis code is set
in the other systems.
Q: Is the diagnosis code set?
YES : Troubleshoot for the relevant diagnosis
code.
NO : Replace the engine ECU, and then go to
Step 4.
STEP 4. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is the diagnosis code No. U1426 set?
YES : Replace the ASC-ECU.
NO : This diagnosis is complete.
Group
TOC
35C-84
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Main
Index
Code No. U1427: Engine torque signal error
Code No. U1428: Engine's maximum torque signal error
Code No. U1429: Engine's minimum torque signal error
Code No. U1430: Engine's torque request signal error
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.
DIAGNOSIS CODE SET CONDITIONS
ASC-ECU receives the engine torque-related signals
from the engine ECU via the CAN bus lines. When
the information on trouble is included in these signals, this diagnosis code is stored.
COMMENTS ON TROUBLE SYMPTOM
Current trouble
• Connector(s) or wiring harness in the CAN bus
lines between the ASC-ECU and the
engine-ECU, the power supply system to the
engine-ECU, or the ASC-ECU itself may be
defective.
Past trouble
• If diagnosis code No. U1427, U1428, U1429, or
U1430 is stored as a past trouble, carry out diagnosis with particular emphasis on connector(s)
and wiring harness in the CAN bus line between
the ASC-ECU and the engine ECU, and the
power supply circuit to the engine ECU. For diagnosis procedures, refer to How to treat past trouble (refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points
P.00-13).
NOTE: For a past trouble, you can not find it by the
M.U.T.-III CAN bus diagnostics even if there is
any failure in CAN bus lines. In this case, refer to
GROUP 00 − How to Use Troubleshooting/Inspection Service Points P.00-13 and check
the CAN bus lines. You can narrow down the
possible cause of the trouble by referring to the
diagnosis code, which is set regarding the CAN
communication-linked ECUs. (Refer to GROUP
54D − CAN Bus Line Diagnostic Flow P.54D-7.)
Probable causes
• Engine ECU malfunction
• ASC-ECU malfunction
• Damaged wiring harness and connectors
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
Q: Is the diagnosis code No. U1427, U1428, U1429, or
U1430 set?
YES : Go to Step 3.
NO : This diagnosis is complete.
STEP 3. M.U.T.-III diagnosis code for other
systems
Use M.U.T.-III to check that the diagnosis code is set
in the other systems.
Q: Is the diagnosis code set?
YES : Troubleshoot for the relevant diagnosis
code.
NO : Replace the engine ECU, and then go to
Step 4.
STEP 4. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON
Q: Is the diagnosis code No. U1427, U1428, U1429, or
U1430 set?
YES : Replace the ASC-ECU.
NO : This diagnosis is complete.
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
35C-85
TROUBLE SYMPTOM CHART
M1357001000013
Main
Index
CAUTION
During diagnosis, a diagnosis code associated with other system may be set when the ignition switch
is turned on with connector(s) disconnected. On completion, check if the diagnosis code is set. If the Group
diagnosis code has been set, erase that code.
TOC
Trouble symptom
Inspection
procedure
number
Reference page
Cannot communicate with ASC-ECU using the M.U.T.-III
1
P.35C-85
ASC-ECU power supply circuit system
2
P.35C-86
The ABS warning lamp and the ASC indicator lamp don't illuminate when
the ignition switch is turned ON.
3
P.35C-89
ABS warning lamp and ASC indicator lamp does not extinguish after the
engine is started.
4
P.35C-90
Brake warning lamp does not illuminate at all.
5
P.35C-91
Brake warning lamp does not illuminate when the parking brake is
operated. (illuminates when the bulb check is performed.)
6
P.35C-92
Brake warning lamp does not illuminate when the brake fluid level is low
(illuminates when the parking brake is operated).
7
P.35C-94
Brake warning lamp does not extinguish when the ignition switch is ON
(remains illuminated).
8
P.35C-96
Stability control system operates too frequently (no diagnosis code is set). 9
P.35C-100
Steering wheel sensor power supply system
10
P.35C-102
G and yaw rate sensor power supply circuit
11
P.35C-105
SYMPTOM PROCEDURES
Inspection Procedure 1: Cannot communicate with ASC-ECU using the M.U.T.-III
COMMENTS ON TROUBLE SYMPTOM
DIAGNOSTIC PROCEDURE
If the M.U.T.-III cannot communicate with the
ASC-ECU, the CAN bus lines may be defective.
When malfunction occurs in the ASC-ECU power
supply circuit and earth circuit, the CAN bus diagnosis detects the abnormality. This symptom also
appears when an incorrect vehicle model is selected
on the M.U.T.-III.
STEP 1. M.U.T.-III selected vehicle model
confirmation
Confirm which vehicle model is selected on the
M.U.T.-III vehicle information screen.
PROBABLE CAUSES
• Damaged wiring harness and connectors
• ASC-ECU malfunction
Q: Is the correct vehicle model selected?
YES : Go to Step 2.
NO : Input the vehicle information correctly.
STEP 2. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Replace the ASC-ECU.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.)
35C-86
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Inspection Procedure 2: ASC-ECU power supply circuit malfunction
ASC-ECU Power Source Circuit
IGNITION
SWITCH (IG1)
ASC-ECU
Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple
OPERATION
• The ASC-ECU is energised by the ignition switch
(IG1) through multi-purpose fuse 40 and the
ASC-ECU terminal No. 40.
• When malfunction occurs in ASC-ECU power
supply, the communication with M.U.T.-III
becomes unavailable.
PROBABLE CAUSES
•
•
•
•
Damaged wiring harness and connectors
Battery failure
Charging system failed
ASC-ECU malfunction
DIAGNOSTIC PROCEDURE
STEP 1. Battery terminal voltage measurement
(1) Ignition switch: ON
(2) Engine: Started
(3) Measure the voltage between the battery
terminals.
OK: 10V or more
Q: Is the check result normal?
YES : Go to Step 2.
NO : Diagnose the charging system. (Refer to
GROUP 16 − On-vehicle Service P.16-6.)
Main
Index
Group
TOC
35C-87
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 2. Connector check: A-05 ASC-ECU
connector
Connector: A-05
STEP 3. Voltage measurement: A-05 ASC-ECU
connector
Main
Index
Connector: A-05
Group
TOC
A-05(Black)
A-05(Black)
Harness side
Harness side
AC601083 AB
AC601083 AB
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the damaged connector.
MB991984
Check connector
ASC-ECU
ASC-ECU harness connector
AC601086AD
(1) Disconnect A-05 ASC-ECU connector, and
connect the ABS check harness (Special tool:
MB991984) to the ASC-ECU side connector and
the harness side connector.
(2) Ignition switch: ON
(3) Engine: Started
(4) Measure the voltage between the ABS check
harness (Special tool: MB991984) connector
terminal No. 40 and the body earth.
OK: 10 V or more
Q: Is the check result normal?
YES : Go to Step 4.
NO : Repair the harness wire between A-05
ASC-ECU connector terminal No. 40 and
the ignition switch (IG1).
35C-88
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 4. Measure the resistance at A-05 ASC-ECU
connector.
Connector: A-05
Harness side
AC601083 AB
Check connector
ASC-ECU
ASC-ECU harness connector
Q: Can the ASC-ECU communicate with the M.U.T.-III?
YES : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : Replace the ASC-ECU.
A-05(Black)
MB991984
STEP 5. Retest the system.
AC601085AI
(1) Disconnect the A-05 ASC-ECU connector, and
connect the ABS check harness (Special tool:
MB991984) to the harness side connector.
NOTE: . Do not connect the ABS check harness
(Special tool: MB991984) to the ASC-ECU.
(2) Measure the resistance between A-05 ASC-ECU
connector terminal No. 43 and the body earth.
OK: Continuity exists (2 Ω or less)
Q: Is the check result normal?
YES : . Go to Step 5.
NO : . Repair the harness wire between A-05
ASC-ECU connector terminal No. 43 and
the body earth.
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
35C-89
Main
Inspection Procedure 3: The ABS warning lamp and the ASC indicator lamp don't illuminate when the Index
ignition switch is turned ON.
COMMENTS ON TROUBLE SYMPTOM
• Drive signal of the ABS warning lamp and the
ASC indicator lamp (including bulb check) is sent
from the ASC-ECU to the combination meter
through the CAN communication lines.
• If the combination meter detects a ASC time-out
due to a failure in abnormal CAN communication,
the combination meter illuminates the lamp.
• The ABS warning lamp and the ASC indicator
lamp are non-replaceable LED. If the lamp is
blown, replace the combination meter.
• Perform the actuator test to illuminate the lamps
in the combination meter. If the lamp does not
illuminate, replace the combination meter assembly. If the lamp illuminates, replace the ASC-ECU.
PROBABLE CAUSES
• Damaged wiring harness and connectors
• Combination meter assembly malfunction
• ASC-ECU malfunction
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III actuator test for other systems
(1) Ignition switch: ON
(2) Execute combination meter actuator test.
• Item A0: Indicator lamp and warning lamp
OK: Illuminates
Q: Is the check result normal?
YES : Go to Step 2.
NO : Replace the combination meter assembly.
STEP 2. M.U.T.-III diagnosis code for other
systems
Check if the combination meter-related diagnosis
code is set.
Q: Is the diagnosis code set?
YES : Troubleshoot the combination meter. (Refer
to GROUP 54A − Troubleshooting
P.54A-31)
NO : Replace the ASC-ECU, and then go to Step
3.
STEP 3. Retest the system.
Q: Do the ABS warning lamp and the ASC indicator
lamp illuminate when the ignition switch is turned
ON?
YES : This diagnosis is complete.
NO : Replace the combination meter assembly.
Group
TOC
35C-90
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Main
Inspection Procedure 4: ABS warning lamp and ASC indicator lamp do not extinguish after the engine Index
is started.
COMMENTS ON TROUBLE SYMPTOM
• Drive signal of the ABS warning lamp and the
ASC indicator lamp (including bulb check) is sent
from the ASC-ECU to the combination meter
through the CAN communication lines.
• If the combination meter detects a ASC time-out
due to a failure in abnormal CAN communication,
the combination meter illuminates the lamp.
• When malfunction occurs in the ASC-ECU power
supply (i.e. excessively high resistance in the
power supply or earth lines), this trouble symptom will appear, but the diagnosis code will not be
set. If the vehicle is run at 15 km/h or more after
that, the ASC-ECU set the diagnosis code No.
C1861.
• Perform the actuator test to extinguish the lamp
in the combination meter. If the lamp does not
extinguish, replace the combination meter ASSY.
If the lamp extinguishes, replace the ASC-ECU.
• The ABS warning lamp and the ASC indicator
lamp are non-replaceable LED. If the lamp is
blown, replace the combination meter.
• When malfunction occurs in the steering wheel
sensor or the ASC-ECU power supply system
and earth system, the ABS warning lamp may
illuminate when the ignition system is turned ON
even after returning to the normal condition. In
this case, the ABS warning lamp goes out when
the ASC-ECU finishes self-check operation of the
following items.
• Steering wheel sensor: Self-check operation
is finished at approximately 10km/h.
• ASC-ECU: Self-check operation is finished at
approximately 15 km/h.
PROBABLE CAUSES
• Damaged wiring harness and connectors
• Combination meter assembly malfunction
• ASC-ECU malfunction
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the CAN bus lines. (Refer to GROUP
54D − Troubleshooting P.54D-13.) On
completion, go to Step 2.
STEP 2. M.U.T.-III diagnosis code
Q: Is the diagnosis code No. C1861 set?
YES : Carry out the diagnosis for the diagnosis
code.(Refer to P.35C-72.)
NO : Go to Step 3.
STEP 3. M.U.T.-III actuator test for other systems
(1) Ignition switch: ON
(2) Execute combination meter actuator test.
• Item A1: Indicator lamp and warning lamp
OK: OFF
Q: Is the check result normal?
YES : Replace the ASC-ECU, and then go to Step
4.
NO : Replace the combination meter assembly.
STEP 4. Retest the system.
Q: Do the ABS warning lamp and the ASC indicator
lamp illuminate when the ignition switch is turned
ON?
YES : This diagnosis is complete.
NO : Replace the combination meter assembly.
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
35C-91
Inspection Procedure 5: Brake warning lamp does not illuminate at all.
COMMENTS ON TROUBLE SYMPTOM
• When EBD is abnormal and the brake fluid level
is low, the ASC-ECU sends the brake warning
lamp drive signal to the combination meter
through the CAN communication lines.
• The ASC-ECU sends the lamp drive signal to the
combination meter during a bulb check (for three
seconds after the ignition switch is turned on)
through the CAN communication lines, and then
the combination meter activates the lamp.
• If the combination meter detects a ASC time-out
due to a failure in abnormal CAN communication,
the combination meter illuminates the lamp.
PROBABLE CAUSES
• Damaged wiring harness and connectors
• Combination meter assembly malfunction
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III actuator test for other systems
(1) Ignition switch: ON
(2) Execute combination meter actuator test.
• Item A0: Indicator lamp and warning lamp
OK: Illuminates
Q: Is the check result normal?
YES : . Go to Step 2.
NO : . Replace the combination meter assembly.
STEP 2. M.U.T.-III diagnosis code for other
systems
Check if the combination meter-related diagnosis
code is set.
Q: Is the diagnosis code set?
YES : Troubleshoot the combination meter. (Refer
to GROUP 54A − Troubleshooting
P.54A-31)
NO : Replace the ASC-ECU, and then go to Step
3.
STEP 3. Retest the system.
Q: Do the ABS warning lamp and the ASC indicator
lamp illuminate when the ignition switch is turned
ON?
YES : This diagnosis is complete.
NO : Replace the combination meter assembly.
Main
Index
Group
TOC
35C-92
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Main
Inspection Procedure 6: Brake warning lamp does not illuminate when the parking brake is operated. Index
(Illuminates when the bulb check is operated.)
Group
TOC
Parking Brake Switch Circuit
ASC-ECU
PARKING
BRAKE
SWITCH
COMMENTS ON TROUBLE SYMPTOM
• When the parking brake is operated, the
ASC-ECU sends the brake warning lamp drive
signal to the combination meter through the CAN
communication lines.
• The ASC-ECU sends the lamp drive signal to the
combination meter during a bulb check (for three
seconds after the ignition switch is turned on)
through the CAN communication lines, and then
the combination meter activates the lamp.
• If the combination meter detects a ASC time-out
due to a failure in abnormal CAN communication,
the combination meter illuminates the lamp.
PROBABLE CAUSES
•
•
•
•
Damaged wiring harness and connectors
Parking brake switch malfunction
Combination meter assembly malfunction
ASC-ECU malfunction
Wire colour code
B : Black LG : Light green
G : Green L : Blue
W : White Y : Yellow
SB : Sky blue BR : Brown
O : Orange GR : Grey
R : Red P : Pink
V : Violet PU : Purple
STEP 2. Check A-05 ASC-ECU connector and
C-44 parking brake switch connector.
Connector: A-05
A-05(Black)
Harness side
AC601083 AB
Connector: C-44
Harness side
DIAGNOSTIC PROCEDURE
C-44(Black)
STEP 1. M.U.T.-III data list
Using the data list, check that the parking brake input
signal is normal. (Refer to P.35C-109.)
• Item No.28: side brake switch
Q: Is the check result normal?
YES : Go to Step 6.
NO : Go to Step 2.
AC601093 AD
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair.
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 3. Check the parking brake switch as single
unit.
Refer to GROUP 36 − On-vehicle Service P.36-5.
Q: Is the check result normal?
YES : Go to Step 4.
NO : Replace the parking brake switch. (Refer to
GROUP 36 − Parking brake lever P.36-7.)
STEP 4. Measure the resistance at A-05 ASC-ECU
connector.
35C-93
(2) Pull the parking brake lever and turn the parking Main
brake switch to ON.
Index
(3) Measure the resistance between A-05 ASC-ECU
connector terminal No. 27 and the body earth.
Group
OK: Continuity exists (2 Ω or less)
Q: Is the check result normal?
YES : Go to Step 5.
NO : Repair the harness wire between A-05
ASC-ECU connector terminal No. 27 and
C-44 parking brake switch connector
terminal No. 1.
Connector: A-05
STEP 5. Retest the system.
Q: Does the brake warning lamp illuminate when the
parking brake is operated?
YES : Intermittent malfunction (Refer to GROUP
A-05(Black)
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : Replace the ASC-ECU.
Harness side
AC601083 AB
STEP 6. Retest the system.
Q: Does the brake warning lamp illuminate when the
parking brake is operated?
YES : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : Replace the combination meter assembly,
and then go to Step 7.
STEP 7. Retest the system.
Q: Does the brake warning lamp illuminate when the
parking brake is operated?
YES : This diagnosis is complete.
NO : Replace the ASC-ECU.
MB991984
Check connector
ASC-ECU
ASC-ECU harness connector
AC601085AJ
AC601085
(1) Disconnect the A-05 ASC-ECU connector, and
connect the ABS check harness (Special tool:
MB991984) to the harness side connector.
NOTE: . Do not connect the ABS check harness
(Special tool: MB991984) to the ASC-ECU.
TOC
35C-94
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Inspection Procedure 7: Brake warning lamp does not illuminate when the brake fluid level is low.
illuminates when the parking brake is operated.)
Brake Fluid Level Switch Circuit
ASC-ECU
BRAKE
FLUID
LEVEL
SWITCH
Wire colour code
B : Black LG : Light green
G : Green L : Blue
W : White Y : Yellow
SB : Sky blue BR : Brown
O : Orange GR : Grey
R : Red P : Pink
V : Violet PU : Purple
(EARTH 7)
COMMENTS ON TROUBLE SYMPTOM
• When the brake fluid level is low, the ASC-ECU
sends the brake warning lamp drive signal to the
combination meter through the CAN communication lines.
• The ASC-ECU sends the lamp drive signal to the
combination meter during a bulb check (for three
seconds after the ignition switch is turned on)
through the CAN communication lines, and then
the combination meter activates the lamp.
• If the combination meter detects a ASC time-out
due to a failure in abnormal CAN communication,
the combination meter illuminates the lamp.
PROBABLE CAUSES
•
•
•
•
Damaged wiring harness and connectors
Brake fluid level switch malfunction
Combination meter assembly malfunction
ASC-ECU malfunction
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III data list
Using the data list, check that the brake fluid level
switch signal is normal.(Refer to P.35C-109.)
• Item No. 32: Brake fluid level switch
Q: Is the check result normal?
YES : Go to Step 6.
NO : Go to Step 2.
Main
Index
Group
TOC
35C-95
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 2. Check A-03 brake fluid level switch
connector and A-05 ASC-ECU connector.
Connector: A-03
A-03(Grey)
STEP 4. Measure the resistance at A-03 brake
fluid level switch connector and A-05 ASC-ECU
connector.
Group
TOC
Connector: A-03, A-05
A-03(Grey)
A-05
(Black)
Harness
side
AC601084 AD
Connector: A-05
A-03: Harness side
A-05(Black)
Harness side
A-05: Harness side
AC601083 AB
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair.
STEP 3. Check the brake fluid level switch as a
single unit.
Refer to GROUP 35A − On-vehicle Service
P.35A-11.
Q: Is the check result normal?
YES : Go to Step 4.
NO : Replace the reservoir assembly. (Refer to
GROUP 35A − Master cylinder assembly
and brake booster P.35A-23.)
Main
Index
AC601110AB
(1) Disconnect A-03 brake fluid level switch
connector and A-05 ASC-ECU connector.
(2) Make the brake fluid below the specified level,
and turn ON the brake fluid level switch.
(3) Measure the resistance between A-03 brake fluid
level switch connector terminal No. 2 and A-05
ASC-ECU connector terminal No. 32.
OK: Continuity exists (2 Ω or less)
Q: Is the check result normal?
YES : Go to Step 5.
NO : Repair the harness wire between A-03
brake fluid level switch connector terminal
No. 2 and A-05 ASC-ECU connector
terminal No. 32.
35C-96
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 5. Measure the resistance at A-03 brake
fluid level switch connector.
Connector: A-03
A-03(Grey)
STEP 6. Retest the system.
Q: Does the brake warning lamp illuminate when the
brake fluid level is low?
YES : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : Replace the combination meter assembly,
and then go to Step 7.
Harness side
STEP 7. Retest the system.
AC601084 AE
(1) Disconnect A-03 brake fluid level switch
connector.
(2) Measure the resistance between A-03 brake fluid
level switch connector terminal No. 2 and the
body earth.
OK: Continuity exists (2 Ω or less)
Q: Is the check result normal?
YES : Go to Step 8.
NO : Repair the harness wire between A-03
brake fluid level switch connector terminal
No. 2 and body earth.
Q: Does the brake warning lamp illuminate when the
brake fluid level is low?
YES : This diagnosis is complete.
NO : Replace the ASC-ECU.
STEP 8. Retest the system.
Q: Does the brake warning lamp illuminate when the
brake fluid level is low?
YES : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : Replace the ASC-ECU.
Inspection Procedure 8: Brake warning lamp does not extinguish when the ignition switch is ON.
(Always illuminates)
Brake Fluid Level Switch and Parking Brake Switch Circuit
ASC-ECU
BRAKE
FLUID
LEVEL
SWITCH
(EARTH 7)
PARKING
BRAKE
SWITCH
Wire colour code
B : Black LG : Light green
G : Green L : Blue
W : White Y : Yellow
SB : Sky blue BR : Brown
O : Orange GR : Grey
R : Red P : Pink
V : Violet PU : Purple
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
COMMENTS ON TROUBLE SYMPTOM
• The brake warning lamp drive signal at the EBD
system error and the low brake fluid level is sent
from the ASC-ECU to the combination meter
through the CAN communication lines.
• If the combination meter detects a ASC time-out
due to a failure in the power supply to the
ASC-ECU or abnormal CAN communication, the
combination meter illuminates the lamp.
• The ASC-ECU sends the lamp drive signal to the
combination meter during a bulb check (for three
seconds after the ignition switch is turned on)
through the CAN communication lines, and then
the combination meter activates the lamp.
• If the combination meter detects a ASC time-out
due to a failure in abnormal CAN communication,
the combination meter illuminates the lamp.
• This symptom appears when the brake fluid level
switch or the parking brake switch is shorted to
earth. When the brake fluid level witch is shorted
to earth, the diagnosis code No. C1345 is set.
STEP 3. Check the brake fluid level switch as a
single unit.
Refer to GROUP 35A − On-vehicle Service
P.35A-11.
Q: Is the check result normal?
YES : Go to Step 4.
NO : Replace the reservoir assembly. (Refer to
GROUP 35A − Master cylinder assembly
and brake booster P.35A-23.)
STEP 4. Check A-03 brake fluid level switch
connector and A-05 ASC-ECU connector.
Connector: A-03
A-03(Grey)
Harness
side
PROBABLE CAUSES
•
•
•
•
•
Damaged wiring harness and connectors
Parking brake switch malfunction
Brake fluid level switch malfunction
Combination meter assembly malfunction
ASC-ECU malfunction
DIAGNOSTIC PROCEDURE
35C-97
AC601084 AD
Connector: A-05
A-05(Black)
Harness side
STEP 1. Check the brake fluid level.
Check that the brake fluid is filled to the specified.
Q: Is the check result normal?
YES : Check the brake pad remaining thickness,
fill the brake fluid to the specified, and then
go to Step 12.
NO : Go to Step 2.
STEP 2. M.U.T.-III data list
Using the data list, check that the parking brake input
signal and the brake fluid level switch signal are normal.(Refer to P.35C-109.)
• Item No. 28: Side brake switch
• Item No. 32: Brake fluid level switch
Q: Is the check result normal?
YES : Go to Step 10.
NO : Go to Step 3.
AC601083 AB
Q: Is the check result normal?
YES : Go to Step 5.
NO : Repair the A-03 brake fluid level switch
connector and the A-05 ASC-ECU
connector.
Main
Index
Group
TOC
35C-98
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 5. Measure the resistance at A-03 brake
fluid level switch connector and A-05 ASC-ECU
connector.
STEP 6. Measure the resistance at A-03 brake
fluid level switch connector.
Connector: A-03
A-03(Grey)
Connector: A-03, A-05
A-03(Grey)
A-05
(Black)
Group
TOC
Harness side
AC601084 AE
(1) Disconnect A-03 brake fluid level switch
connector.
(2) Measure the resistance between A-03 brake fluid
level switch connector terminal No. 2 and the
body earth.
OK: Continuity exists (2 Ω or less)
A-03: Harness side
Q: Is the check result normal?
YES : Go to Step 7.
NO : Repair the harness wire between A-03
A-05: Harness side
AC601110AB
(1) Disconnect A-03 brake fluid level switch
connector and A-05 ASC-ECU connector.
(2) Make the brake fluid below the specified level,
and turn ON the brake fluid level switch.
(3) Measure the resistance between A-03 brake fluid
level switch connector terminal No. 2 and A-05
ASC-ECU connector terminal No. 32.
OK: Continuity exists (2 Ω or less)
Q: Is the check result normal?
YES : Go to Step 6.
NO : Repair the harness wire between A-03
brake fluid level switch connector terminal
No. 2 and A-05 ASC-ECU connector
terminal No. 32.
Main
Index
brake fluid level switch connector terminal
No. 2 and body earth.
STEP 7. Check the parking brake switch as single
unit.
Refer to GROUP 36 − On-vehicle Service P.36-5.
Q: Is the check result normal?
YES : Go to Step 8.
NO : Replace the parking brake switch. (Refer to
GROUP 36 − Parking brake lever P.36-7.)
35C-99
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 8. Check A-05 ASC-ECU connector and
C-42 parking brake switch connector.
Connector: A-05
Main
STEP 9. Measure the resistance at A-05 ASC-ECU
Index
connector.
Connector: A-05
Group
TOC
A-05(Black)
A-05(Black)
Harness side
Harness side
AC601083 AB
AC601083 AB
Connector: C-44
Harness side
C-44(Black)
AC601093 AD
Q: Is the check result normal?
YES : Go to Step 9.
NO : Repair.
MB991984
Check connector
ASC-ECU
ASC-ECU harness connector
AC601085AJ
AC601085
(1) Disconnect the A-05 ASC-ECU connector.
(2) Pull the parking brake lever and turn the parking
brake switch to ON.
(3) Measure the resistance between A-05 ASC-ECU
connector terminal No. 27 and the body earth.
OK: Continuity exists (2 Ω or less)
Q: Is the check result normal?
YES : Go to Step 12.
NO : Repair the harness wire between A-05
ASC-ECU connector terminal No. 27 and
C-42 parking brake switch connector
terminal No. 1.
35C-100
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 10. Retest the system.
STEP 11. Retest the system.
Q: Does the brake warning lamp go off when the
ignition switch is ON?
YES : Intermittent malfunction (Refer to GROUP
Q: Does the brake warning lamp go off when the
ignition switch is ON?
YES : This diagnosis is complete.
NO : Replace the ASC-ECU.
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : Replace the combination meter assembly,
and then go to Step 11.
STEP 12. Retest the system.
Q: Does the brake warning lamp go off when the
ignition switch is ON?
YES : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : Replace the ASC-ECU.
Inspection Procedure 9: The stability control system operates too frequently. (the diagnosis code is
not set.)
COMMENTS ON TROUBLE SYMPTOM
• This symptom does not appear due to a failure in
wiring harness (open or short circuit, or excessive
resistance). Therefore, if the sensors are installed
properly and the check result does not indicate
any problems, replace the ASC-ECU.
• This symptom does not appear at steering wheel
sensor calibration. (The diagnosis code is set.)
NOTE: If the steering neutral position fluctuates
slightly, the ASC system may activate early.
PROBABLE CAUSES
•
•
•
•
•
•
Wheel speed sensor malfunction
G and yaw rate sensor malfunction
Steering wheel sensor malfunction
Wheel bearing malfunction
ASC-ECU malfunction
Malfunction of magnetic encoder for wheel speed
detection
STEP 2. M.U.T.-III data list
Using the data list, check the G and yaw rate sensor
output value.(Refer to P.35C-109.)
• Item No. 14: Lateral G-sensor
• Item No.17: Yaw rate sensor
Q: Is the check result normal?
YES : Go to Step 3.
NO : Replace the G and yaw rate sensor.
STEP 3. Steering wheel sensor installation state
check
Check that the steering wheel sensor is installed correctly.
Q: Is the check result normal?
YES : Go to Step 4.
NO : Install the steering wheel sensor correctly.
DIAGNOSTIC PROCEDURE
STEP 4. M.U.T.-III data list
Using the data list, check the steering sensor output
value.(Refer to P.35C-109.)
• Item No. 16: Steering angle sensor
STEP 1. G and yaw rate sensor installation check
Check that the G and yaw rate sensor is installed
correctly.
Q: Is the check result normal?
YES : Go to Step 5.
NO : Replace the steering wheel sensor.
Q: Is the check result normal?
YES : Go to Step 2.
NO : Reinstall the G and yaw rate sensor
correctly.
STEP 5. Check how wheel speed sensor is
installed.
Check that the wheel speed sensor is installed correctly.
Q: Is the check result normal?
YES : Go to Step 6.
NO : Reinstall the wheel speed sensor correctly.
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 6. Check for wheel speed sensor as a
single unit
Refer to GROUP 35B − Wheel speed sensor
P.35B-81.
Q: Is the check result normal?
YES : Go to Step 7.
NO : Replace the wheel speed sensor.
STEP 7. Wheel speed detection magnetic
encoder check
<Front>
35C-101
Main
STEP 8. Check the wheel bearing.
Index
NOTE: Loose wheel bearing may increase the gap
between the wheel speed sensor and the wheel
speed detection magnet encoder. Check each wheel Group
bearing for looseness.
TOC
Front: Refer to GROUP 26 − On-vehicle Service
P.26-5.
Rear: Refer to GROUP 27 − On-vehicle Service
P.27-3.
Q: Is the check result normal?
YES : Go to Step 9.
NO <Front> : Replace the wheel bearing. (Refer to
GROUP 26 − Front Axle Hub Assembly
P.26-13.)
NO <Rear> : Replace the rear hub assembly.
(Refer to GROUP 27 − Rear Axle Hub
Assembly P.27-6.)
Encoder
STEP 9. Retest the system.
Q: Does the stability control system operate too
frequently?
YES : Replace the ASC-ECU.
NO : Intermittent malfunction (Refer to GROUP
<Rear>
00 − How to Cope with Intermittent
Malfunction P.00-13.)
Encoder
AC600965AB
Check the wheel speed detection magnetic encoder
for adhesion of foreign materials or deformation.
NOTE: For the rear wheel speed detection magnetic
encoder, check from the mounting hole of the wheel
speed sensor by rotating the rear hub.
Q: Is the check result normal?
YES : . Go to Step 8.
NO <Front> : . If foreign objects are found, clean
the magnetic encoder for wheel speed
detection. When the encoder is deformed,
replace the wheel bearing. (Refer to
GROUP 26 − Front Axle Hub Assembly
P.26-13.)
NO <Rear> : . If foreign objects are found, clean
the magnetic encoder for wheel speed
detection. When the encoder is deformed,
replace the rear hub assembly. (Refer to
GROUP 27 − Rear Axle Hub Assembly
P.27-6.)
35C-102
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Inspection Procedure 10: Steering wheel sensor power supply system
Steering Wheel Sensor Power Source Circuit
IGNITION
SWITCH (IG1)
STEERING
WHEEL
SENSOR
Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple
OPERATION
The steering wheel sensor is energised by the ignition switch (IG1) through the multi-purpose fuse No.
40 and the steering wheel sensor terminal No. 2.
PROBABLE CAUSES
• Damaged wiring harness and connectors
• Steering wheel sensor malfunction
Main
Index
Group
TOC
35C-103
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
DIAGNOSTIC PROCEDURE
STEP 1. Connector inspection: B-22 joint
connector, B-131 junction block connector, B-142
steering wheel sensor connector
Connector: B-22
STEP 2. Measure the resistance between B-142
steering wheel sensor connector and B-131
junction block connector.
Connector: B-131
J/B
J/B
(Back
i
view)
û
j
Harness side
Harness side
B-131
AC601113 AB
B-22
Connector: B-142
AC601112 AB
Harness side
Connector: B-131
J/B
J/B
(Back
i
view)
û
j
Harness side
B-131
B-142
AC601114AB
AC601113 AB
Connector: B-142
Harness side
B-142: Harness side
B-131: Harness side
B-142
AC601114AB
Q: Is the check result normal?
YES : Go to Step 2.
NO : Repair the damaged connector.
AC601116AB
(1) Disconnect B-142 steering wheel sensor
connector and B-131 junction block connector.
(2) Measure the resistance between B-142 steering
wheel sensor connector terminal No. 2 and B-131
junction block connector terminal No. 30.
OK: Continuity exists (2 Ω or less)
Q: Is the check result normal?
YES : Go to Step 4.
NO : Go to Step 3.
Main
Index
Group
TOC
35C-104
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 3. Check the wiring harness between B-142
steering wheel sensor connector terminal No. 2
and the ignition switch (IG1).
Connectors: B-141, B-142
B-142: Harness side
B-141: Harness side
(2) Measure the resistance between B-142 steering
wheel sensor connector terminal No. 1 and the
body earth.
OK: Continuity exists (2 Ω or less)
Q: Is the check result normal?
YES : Go to Step 5.
NO : Repair the wiring harness between B-142
steering wheel sensor connector terminal
No. 1 and the body earth.
B-142
B-141
AC601114 AC
Check the power supply line for open circuit.
Q: Is the check result normal?
YES : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : Repair the wiring harness between B-142
steering wheel sensor connector terminal
No. 2 and the ignition switch (IG1).
STEP 4. Measure the resistance at B-142 steering
wheel sensor connector.
Connector: B-142
Harness side
B-142
AC601114AB
B-142: Harness side
AC601118AB
(1) Disconnect B-142 steering wheel sensor
connector, and measure at the wiring
harness-side connector.
STEP 5. Retest the system.
Check that the steering wheel sensor communicates
with the ASC-ECU normally.
NOTE: When the steering wheel sensor related diagnosis code is not set to ACS-ECU and the steering
wheel sensor is normal at the M.U.T.-III CAN bus
diagnosis, the communication with the steering
wheel sensor is normal.
Q: Is the check result normal?
YES : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : Replace the steering wheel sensor.
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
35C-105
Inspection Procedure 11: G and yaw rate sensor power supply circuit
G and Yaw Rate Sensor Power Source Circuit
G AND
YAW RATE
SENSOR
Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple
OPERATION
The G and yaw rate sensor is energised by the ignition switch (IG1) through the multi-purpose fuse No.
40 and the G and yaw rate sensor terminal No. 1.
PROBABLE CAUSES
• Damaged wiring harness and connectors
• G and yaw rate sensor malfunction
Main
Index
Group
TOC
35C-106
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
DIAGNOSTIC PROCEDURE
STEP 1. Connector check: C-45 G and yaw rate
sensor connector, B-22 Joint connector and
B-131 junction block connector
Connector: C-45
STEP 2. Measure the resistance between C-45 G
and yaw rate sensor connector and B-131
junction block connector.
Group
TOC
Connector: C-45
Harness side
Harness side
C-45(Black)
AC601093 AC
C-45(Black)
AC601093 AC
Connector: B-22
Connector: B-131
J/B
J/B
(Back
i
view)
û
j
Harness side
Harness side
B-131
AC601113 AB
B-22
AC601112 AB
Connector: B-131
J/B
J/B
(Back
i
view)
û
j
(1) Disconnect C-45 G and yaw rate sensor
connector and connect B-131 junction block
connector.
Harness side
B-131
B-210 connector:
Harness side
AC601113 AB
Q: Is the check result normal?
YES : Go to Step 2.
NO : Repair the damaged connector.
Main
Index
Test
harness
Test
harness
C-26 connector:
Harness side
AC314017AD
AC314017
(2) Resistance between C-45 G and yaw rate sensor
connector terminal No. 1 and B-131 junction
block connector terminal No. 30
OK: Continuity exists (2 Ω or less)
35C-107
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Q: Is the check result normal?
YES : Go to Step 4.
NO : Go to Step 3.
Main
Index
STEP 3. Check the wiring harness between B-129
junction block connector terminal No. 3 and the
ignition switch (IG1).
Group
TOC
Connector: B-129
J/B
J/B
(Back
i
ûview)j
Test
harness
Harness side
B-129
AC601113 AC
Connector: B-141
C-26 Harness
connector:
Harness side
Harness side
AC313977AM
(2) Resistance between C-45 G and yaw rate sensor
connector terminal No. 4 and the body earth
OK: Continuity exists (2 Ω or less)
B-141
AC601114AD
Q: Is the check result normal?
YES : Go to Step 6.
NO : Go to Step 5.
• Check the power supply line for open circuit.
Q: Is the check result normal?
YES : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : Repair the wiring harness.
STEP 4. Measure the resistance at C-45 G and
yaw rate sensor connector.
STEP 5. Check the harness wire between C-45 G
and yaw rate sensor connector terminal No. 4
and the body earth.
Connector: C-45
Harness side
Connector: C-45
C-45(Black)
Harness side
AC601093 AC
• Check the earth wires for open circuit.
C-45(Black)
AC601093 AC
(1) Disconnect C-45 G and yaw rate sensor
connector, and measure at the harness side.
Q: Is the check result normal?
YES : Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : Repair the wiring harness.
35C-108
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
STEP 6. System retest
Check that the G and yaw rate sensor communicates
with the ASC-ECU normally.
NOTE: When the G and yaw rate sensor related
diagnosis code is not set to ASC-ECU and the G and
yaw rate sensor is not indicated in red at the
M.U.T.-III CAN bus diagnosis, the communication
with the G and yaw rate sensor is normal.
Q: Is the check result normal?
YES : . Intermittent malfunction (Refer to GROUP
00 − How to Cope with Intermittent
Malfunction P.00-13.)
NO : . Replace the G and yaw rate sensor.
Main
Index
Group
TOC
35C-109
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
DATA LIST REFERENCE TABLE
Among the ASC-ECU input data, the following items
can be read by using the M.U.T.-III.
Item
Check items
Check conditions
No.
01
FR wheel speed sensor
02
FL wheel speed sensor
03
RR wheel speed sensor
04
RL wheel speed sensor
05
07
10
11
12
13
14
15
16
17
20
M1357001200017
Normal conditions
Drive the vehicle.
The speedometer display
and the M.U.T.-III display
almost agree with each
other.
Power supply voltage
Always
8 V or more
Valve relay
The ABS, EBD, stability control
system, and TCL are operated.
ON
The ABS, EBD, stability control
system, and TCL are not
operated.
OFF
The brake pedal is depressed.
ON
The brake pedal is released.
OFF
The brake pedal is depressed.
ON
The brake pedal is released.
OFF
The brake pedal is depressed.
OFF
The brake pedal is released.
ON
The brake pedal is depressed.
OFF
The brake pedal is released.
ON
Stop lamp switch (input value)
Stop lamp switch
Brake switch (input value)
Brake switch
Lateral G-sensor (+: right turn, -: left Vehicle stopped (level)
turn)
Running
−1.1 to 1.1 m/s2
Master cylinder pressure sensor
The brake pedal is depressed.
Increases by the amount
of the brake pedal
depression.
The brake pedal is released.
0 −15 bar
Position the steering wheel in a
straight ahead direction.
-5 − 5 °
Running (when ASC-ECS is
judged as normal.)
-500 − 500 °
Single unit check (when the
sensor unit is normal.)
-720 − 720 °
Yaw rate sensor (-: right turn, +: left
turn)
Vehicle stopped
-4 − 4 °/s
Running
-100.2 − 99.8 °/s
FL inlet valve
The ABS, EBD, stability control
system, and TCL are operated.
ON
The ABS, EBD, stability control
system, and TCL are not
operated.
OFF
Steering angle sensor (-: right turn,
+: left turn)
−17.7 to 17.7 m/s2
Main
Index
Group
TOC
35C-110
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Item
No.
Check items
Check conditions
Normal conditions
21
FL outlet valve
The ABS, EBD, stability control
system, and TCL are operated.
ON
The ABS, EBD, stability control
system, and TCL are not
operated.
OFF
The ABS, EBD, stability control
system, and TCL are operated.
ON
The ABS, EBD, stability control
system, and TCL are not
operated.
OFF
The ABS, EBD, stability control
system, and TCL are operated.
ON
The ABS, EBD, stability control
system, and TCL are not
operated.
OFF
The ABS, EBD, stability control
system, and TCL are operated.
ON
The ABS, EBD, stability control
system, and TCL are not
operated.
OFF
The ABS, EBD, stability control
system, and TCL are operated.
ON
The ABS, EBD, stability control
system, and TCL are not
operated.
OFF
The ABS, EBD, stability control
system, and TCL are operated.
ON
The ABS, EBD, stability control
system, and TCL are not
operated.
OFF
The ABS, EBD, stability control
system, and TCL are operated.
ON
The ABS, EBD, stability control
system, and TCL are not
operated.
OFF
22
23
24
25
26
27
28
29
FR inlet valve
FR outlet valve
RL inlet valve
RL outlet valve
RR inlet valve
RR outlet valve
Side brake switch
Pump motor
The parking brake lever is pulled. ON
The parking brake lever is
released.
OFF
The ABS, EBD, stability control
system, and TCL are operated.
ON
The ABS, EBD, stability control
system, and TCL are not
operated.
OFF
Main
Index
Group
TOC
35C-111
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Item
No.
Check items
Check conditions
Normal conditions
30
SAS calibration flag
The steering wheel sensor
calibration is completed.
Completion
The steering wheel sensor
calibration is not completed.
Incompletion
31
SAS fail flag
The steering wheel sensor output Normal
is normal.
The steering wheel sensor output Fail
is abnormal.
32
Brake fluid level switch
The brake fluid level in the brake OFF
fluid reservoir is above "MIN."
The brake fluid level in the brake ON
fluid reservoir is below "MIN."
33
34
35
36
37
ASC OFF switch
FL/RR diagonal suction valve
FR/RL diagonal suction valve
FL/RR diagonal cut valve
FR/RL diagonal cut valve
The ASC OFF switch is pressed. ON
The ASC OFF switch is not
operated.
OFF
The stability control system and
TCL are operated.
ON
The stability control system and
TCL are not operated.
OFF
The stability control system and
TCL are operated.
ON
The stability control system and
TCL are not operated.
OFF
The stability control system and
TCL are operated.
ON
The stability control system and
TCL are not operated.
OFF
The stability control system and
TCL are operated.
ON
The stability control system and
TCL are not operated.
OFF
Main
Index
Group
TOC
35C-112
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
ACTUATOR TEST TABLE
M1357001300014
Using the M.U.T.-III, the following actuators can be
forcibly operated:
NOTE: .
• The ABS, stability control, and TCL are operated
by ASC-ECU.
• When ASC-ECU is disabled due to the fail-safe
function, the actuator test cannot be performed.
• The actuator test can be performed only when
the vehicle is stationary.
• When communicating with the M.U.T.-III, the
brake warning lamp, ABS warning lamp, ASC
warning lamp and ASC OFF indicator lamp
always illuminate.
Main
Index
Group
TOC
Actuator test specifications
Item No.
Check items
Driven component
01
FR wheel ABS
02
FL wheel ABS
03
RR wheel ABS
Solenoid valve for the corresponding
channel of the hydraulic unit and pump
motor (simplified inspection mode)
04
RL wheel ABS
05
FR wheel TCL
06
FL wheel TCL
07
RR wheel TCL
08
RL wheel TCL
09
Engine TCL operation
Outputs the engine torque control signal
(engine torque = 0 N⋅m) to the engine
ECU for three seconds.
35C-113
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Operation pattern of items 01 to 08
Main
Index
MUT-III actuator test
(Item No.05, 06, 07, 08)
start
Cut valve
Suction valve
(TCL/Stability
control)
Group
TOC
Pressure increase
Complete
Hold
Pressure decrease
MUT-III actuator test
(Item No.01, 02, 03, 04)
start
Complete
Pressure increase
Solenoid valve
(ABS)
Hold
Pressure decrease
Drives
Pump motor
Stops
Approx. 0.05s
1s
2s
Approx. 0.01s
AC400776AC
CHECK AT ECU TERMINALS
M1357001400011
TERMINAL VOLTAGE CHECK
1. Operate the lock lever to disconnect the
ASC-ECU harness connector as shown in the
figure.
NOTE: When the ignition switch is turned to "ON,"
ASC-ECU performs the initial check for approx. 3
seconds. Do not measure the terminal voltage
during that period.
MB991984
Check connector
ASC-ECU
ASC-ECU harness connector
A-05: ASC-ECU connector
AC601121AB
3. Terminal layout is shown in the figure.
AC601007AB
2. Connect the ABS check harness (Special tool:
MB991984) to measure the voltages between
each check connector terminal and earth terminal
(No. 43 or 46).
35C-114
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
Terminal Check items
No.
Check conditions
Normal condition
6
Brake switch: OFF (Release the brake pedal.)
Approximately 0 V
Brake switch: ON (Depress the brake pedal.)
System voltage
Stop lamp switch input
8
Wheel speed sensor (RR) Ignition switch: ON
input
0.4 to 1.3 V
10
Wheel speed sensor (RL)
input
Ignition switch: ON
0.4 to 1.3 V
11
Wheel speed sensor (RL)
power supply
Ignition switch: ON
Voltage that is
approx. 0.7 V lower
than the ASC-ECU
power supply
voltage
13
Wheel speed sensor (FL)
input
Ignition switch: ON
0.4 to 1.3 V
23
Brake switch input
Brake switch: ON (Release the brake pedal.)
Approx. 0 V
Brake switch: OFF (Depress the brake pedal.)
System voltage
27
Parking brake switch input Parking brake switch: ON
Parking brake switch: OFF
System voltage
Approx. 0 V
28
Wheel speed sensor (FR) Ignition switch: ON
input
0.4 to 1.3 V
29
Wheel speed sensor (FR) Ignition switch: ON
power supply
Voltage that is
approx. 0.7 V lower
than the ASC-ECU
power supply
voltage
30
Wheel speed sensor (RR) Ignition switch: ON
power supply
Voltage that is
approx. 0.7 V lower
than the ASC-ECU
power supply
voltage
32
Brake fluid level switch
input
Brake fluid level switch: ON
Approx. 0 V
Brake fluid level switch: OFF
System voltage
34
Wheel speed sensor (FL)
power supply
Ignition switch: ON
Voltage that is
approx. 0.7 V lower
than the ASC-ECU
power supply
voltage
40
ASC-ECU power supply
Ignition switch: ON
System voltage
43
ASC-ECU earth, solenoid
valve earth
Always
0V
44
Solenoid valve power
supply (fusible link No. 5)
Always
System voltage
45
Motor power supply
(fusible link No. 3)
Always
System voltage
46
Motor earth
Always
0V
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
TROUBLESHOOTING
CONTINUITY CHECK AT WIRING
HARNESS-SIDE CONNECTOR
MB991984
35C-115
1. Disconnect the A-05 connector, and connect the
ABS check harness (Special tool: MB991984) to
the harness-side connector.
NOTE: Do not connect the ABS check harness
(Special tool: MB991984) to the ASC-ECU.
2. Check the continuity between terminals shown in
the chart below.
3. Terminal layout is shown in the figure.
Check connector
ASC-ECU
ASC-ECU harness connector
AC601085AE
Connector terminal number
Signal
Normal condition
43 − body earth
Earth
Continuity exists (2 Ω or less)
46 − body earth
Earth
Continuity exists (2 Ω or less)
Main
Index
Group
TOC
35C-116
ACTIVE STABILITY CONTROL SYSTEM (ASC)
ON-VEHICLE SERVICE
ON-VEHICLE SERVICE
HYDRAULIC UNIT (HU) CHECK
M1357001600015
1. Raise the vehicle using a jack and support the
specified points with a rigid rack.
CAUTION
Before connecting or disconnecting M.U.T.-III,
always turn the ignition switch to the LOCK
(OFF) position.
2. Before setting M.U.T.-III, turn the ignition key to
the LOCK (OFF) position.
3. Confirm that the shift lever is in the neutral
position, and then start the engine.
Main
Index
4. Use the M.U.T.-III to perform the actuator test with
depressing the brake pedal. When carrying out
the actuator tests, rotate the wheel by hands to
Group
confirm that the braking force changes.
TOC
NOTE: During the actuator test, the brake warning lamp, ABS warning lamp and ASC indicator
lamp illuminate and the ABS/ASC control is prohibited
NOTE: When ASC-ECU is disabled due to the
fail-safe function, the M.U.T.-III actuator test cannot be performed.
ACTIVE STABILITY CONTROL SYSTEM (ASC)
ON-VEHICLE SERVICE
35C-117
Main
Index
<Item No.01, 02, 03, 04>
Depressed
Pedal
operation
Released
Group
TOC
M.U.T.-III actuator test
(Item No.01, 02, 03, 04) start
Pressure increase
Solenoid
valve
position
2s
Pressure hold
Pressure decrease
1s
Lock
Checking
the brake
force
3s
Drag force when the
pedal is free
<Item No.05, 06, 07, 08>
Depressed
Pedal
operation
Released
M.U.T.-III actuator test
(Item No.05, 06, 07, 08) start
Pressure increase
1s
Solenoid valve
position
Pressure hold
2s
Pressure decrease
Lock
Checking
the brake
force
3s
Drag force when the
pedal is free
AC400603AB
5. This is indicated as shown in the above.
6. When any malfunction has been found, take a
necessary action according to the "Judgment
Table."
35C-118
ACTIVE STABILITY CONTROL SYSTEM (ASC)
ON-VEHICLE SERVICE
Judgment Table
Display on
M.U.T.-III
Operation
Test results
01 FR wheel
ABS
02 FL wheel
ABS
03 RR wheel
ABS
04 RL wheel
ABS
• Depress the brake
pedal to lock the
vehicle.
• Select the vehicle
to be inspected
using M.U.T.-III,
perform the
actuator test.
• Rotate the selected
wheel by hands to
confirm the braking
force.
Judgment
Cause
Measures
Braking force
Normal
decreases for 3
seconds from
the lock status.
−
−
The wheel
does not lock
even if the
brake pedal is
depressed.
Clogged brake line
other than hydraulic
unit
Check and
clean the brake
line.
Clogged hydraulic
circuit in the hydraulic
unit
Replace the
hydraulic unit
assembly.
Faulty routing of
hydraulic unit brake
tube
Route the
brake tube
correctly.
Error
Braking force
does not
decrease.
Malfunction of
Replace the
hydraulic unit solenoid hydraulic unit
valve operation
assembly.
05 FR wheel
TCL
06 FL wheel
TCL
07 RR wheel
TCL
08 RL wheel
TCL
• Select the vehicle
to be inspected
using M.U.T.-III,
perform the
actuator test.
• Rotate the selected
wheel by hands to
confirm the braking
force.
Lock condition Normal
occurs for 3
seconds from
the status
without braking
force.
−
The wheel
does not lock.
• Faulty routing of
Check and
hydraulic unit brake clean the brake
tube
line.
• Clogged brake line
other than hydraulic
unit
Error
Clogged hydraulic
circuit in the hydraulic
unit
7. After the inspection, turn the ignition switch to the
LOCK (OFF) position, and then disconnect
M.U.T.-III.
−
Replace the
hydraulic unit
assembly.
Main
Index
Group
TOC
ACTIVE STABILITY CONTROL SYSTEM (ASC)
ON-VEHICLE SERVICE
MEASURES FOR DISCHARGED
BATTERY
35C-119
STEERING WHEEL SENSOR NEUTRAL
POINT LEARNING
M1357001700012
When starting the engine using a booster cable with
the battery fully discharged, if you begin driving the
vehicle before the battery is fully charged, the engine
misfire may occur and you cannot start the vehicle.
This is because ABS/ASC consumes more electric
current to perform the self-check. In this case,
charge the battery fully.
CAUTION
Because the vehicle posture when applying the
brakes becomes unstable, do not leave ABS/ASC
disabled (for example, ASC-ECU connector disconnection).
Main
Index
M1357001800019
CAUTION
On completion of the following operation, make Group
the steering wheel sensor learn the neutral point. TOC
• Alignment adjustment <Front>
• Steering wheel sensor (column switch assembly) replacement, removal, installation
CAUTION
If ASC-ECU sets the diagnosis code other than
C1394 before calibration, carry out inspection
according to each troubleshooting procedure.
1. Park the vehicle on a level surface with tyres and
steering wheel positioned in a straight ahead
direction.
CAUTION
Before connecting or disconnecting M.U.T.-III,
always turn the ignition switch to the LOCK
(OFF) position.
2. Before setting M.U.T.-III, turn the ignition key to
the LOCK (OFF) position.
3. Ignition switch: ON
4. Select the system from the Menu.
5. On the "System selection" screen, select
"ABS/ASC/ASTC" in the system list, and then
click the "OK" button.
6. Select "Special function" in the "ABS/ASC/ASTC"
field.
7. In the "Special function" filed, select "SAS
calibration."
8. Press the "OK" button.
9. The neutral point is learned.
10.Erase the diagnosis code No. C1394 (Steering
wheel sensor neutral point not learned).
11.Turn the ignition key to the LOCK (OFF) position,
and remove the M.U.T.-III from the vehicle.
35C-120
ACTIVE STABILITY CONTROL SYSTEM (ASC)
ASC OFF SWITCH
ASC OFF SWITCH
Main
Index
REMOVAL AND INSTALLATION
Refer to GROUP 54A - Fog lamp removal and installation.
INSPECTION
M1357003300010
M1357003400017
ASC OFF SWITCH CONTINUITY CHECK
AC601058
1. As shown in the figure, connect the circuit tester
to the ASC OFF switch terminals No. 5 and No. 6
as a single unit.
2. If continuity is detected when the ASC OFF switch
is pressed and if not detected when the switch is
released, the ASC OFF switch is in good
condition.
Group
TOC
35C-121
ACTIVE STABILITY CONTROL SYSTEM (ASC)
HYDRAULIC UNIT
HYDRAULIC UNIT
Main
Index
REMOVAL AND INSTALLATION
M1357002000016
CAUTION
• Be careful when removing the hydraulic unit because it is heavy.
• Never loosen the nuts and the bolts because the hydraulic unit cannot be disassembled.
• Do not drop or shock the hydraulic unit.
• Do not place the hydraulic unit upside down or transversely.
Pre-removal operation
• Brake fluid draining
• Air cleaner body assembly removal (Refer to GROUP 15 −
Air Cleaner P.15-6.)
• Fuel Vapour Canister Removal
(Refer to GROUP 17 − Canister P.17-18.)
Post-installation operation
• Fuel Vapour Canister Installation
(Refer to GROUP 17− Canister P.17-18.)
• Air cleaner body assembly installation (Refer to GROUP
15 − Air Cleaner P.15-6.)
• Brake fluid refilling and air bleeding (Refer to GROUP 35A
− On-vehicle Service, Basic Brake System Bleeding
P.35A-10.)
• Hydraulic Unit Check (Refer to P.35B-76).
2
4
15 ± 2 N·m
2
3
2
4
8 ± 2 N·m
1
2
7
5
6
AC600665AB
>>A<<
1.
2.
3.
4.
Removal steps
ASC-ECU harness connector
Brake tube connection
Fuel vapour canister bracket
Connection of brake tube and
clip
5.
6.
7.
Removal steps (Continued)
Hydraulic unit (ASC-ECU)
Hydraulic unit bracket insulator
Hydraulic unit bracket
Group
TOC
35C-122
ACTIVE STABILITY CONTROL SYSTEM (ASC)
HYDRAULIC UNIT
INSTALLATION SERVICE POINTS
>>A<< BRAKE TUBE INSTALLATION
Yellow
Green
Yellow
AC601030AB
Install each brake tube according to the colour of the
flare nut as shown.
Main
Index
Group
TOC
35C-123
ACTIVE STABILITY CONTROL SYSTEM (ASC)
WHEEL SPEED SENSOR
WHEEL SPEED SENSOR
Main
Index
REMOVAL AND INSTALLATION
M1357002200010
CAUTION
The wheel speed detection magnetic encoder collects metallic particles easily, because it is magnetised. Inspect the wheel speed detection magnetic encoder for foreign material adhesion, and verify
that there is no malfunction in the encoder before assembly.
3
2
2
5
4
1
AC600670AB
>>A<<
1.
2.
3.
Front wheel speed sensor
removal steps
Wheel speed sensor protector
Front wheel speed sensor
Wheel speed sensor bracket
4.
5.
Rear wheel speed sensor
removal steps
Clip
Rear wheel speed sensor
NOTE: .
• The encoder for detecting front wheel speed is a non-disassemble part integrated with the wheel bearing.
• The encoder for detecting rear wheel speed is a non-disassemble part press fitted to the rear hub inner
ring.
INSTALLATION SERVICE POINTS
>>A<< ABS SENSOR PROTECTOR
INSTALLATION
White mark
Front wheel
speed sensor
Wheel speed
sensor protector
AC600671AB
Align the end of the white marking of the front wheel
speed sensor with the edge of the front wheel speed
sensor protector as shown in the figure.
INSPECTION
M1357002300017
Refer to GROUP 35B − Wheel speed sensor.
Group
TOC
35C-124
ACTIVE STABILITY CONTROL SYSTEM (ASC)
G AND YAW LATE SENSOR
G AND YAW LATE SENSOR
Main
Index
REMOVAL AND INSTALLATION
M1357002500011
CAUTION
Do not drop or shock the G and yaw rate sensor.
Pre-removal operation
• Floor Console Assembly Removal (Refer to GROUP 52A
− Floor Console Assembly P.52A-10.)
Group
TOC
Post-installation operation
• Floor Console Assembly Installation (Refer to GROUP
52A − Floor Console Assembly P.52A-10.)
2
1
AC600993AB
1.
2.
Removal steps
Harness connector
G and yaw rate sensor
ACTIVE STABILITY CONTROL SYSTEM (ASC)
STEERING WHEEL SENSOR
35C-125
STEERING WHEEL SENSOR
Main
Index
REMOVAL AND INSTALLATION
M1357002800012
CAUTION
• When centring the clock spring, always remove the clock spring from the column switch in
advance. Otherwise, the sensor may be damaged.
• If the centre of the clock spring is not correctly aligned, the steering wheel may not be turned fully
or the cable inside the clock spring may be broken, causing the SRS air bag to be inoperative or
operated incorrectly.
• Before removing the steering wheel/air bag module assembly, refer to GROUP 52B − Service Precautions P.52B-5 and Air Bag Module Clock Spring P.52B-145.
• When the steering wheel sensor is replaced, always carry out calibration to make ASC-ECU learn
the neutral point. (Refer to P.35C-119.)
Pre-removal operation
• Air bag module assembly and steering wheel assembly
removal (Refer to GROUP 37 − Steering Wheel P.37-90.)
Post-installation operation
• Airbag module assembly and steering wheel assembly
installation (Refer to GROUP 37 − Steering Wheel
P.37-90.)
• Perform steering wheel calibration. (Refer to P.35C-119.)
2
1
AC511706AB
•
Removal steps
Position the front wheels in a straight
ahead direction.
Removal steps (Continued)
1. Clock spring/column switch assembly
(Refer to GROUP 52B − SRS Control
Unit P.52B-143.)
2. Steering wheel sensor
Group
TOC
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