Detroit Diesel Corporation Series 50, Series 60 Engine Troubleshooting Guide

48

FLASH CODE 48 - AIR / FUEL / EGR PRESSURE

LOW OR EGR / TCI / TCO TEMPERATURE LOW

Section Page

48.1

DESCRIPTION OF FLASH CODE 48 .....................................................

48-3

48.2

SAE J1587 EQUIVALENT CODE FOR FLASH CODE 48 .......................

48-4

48.3

TROUBLESHOOTING FLASH CODE 48 ................................................

48-5

Figure 48-1 Fuel Pressure Sensor

48-2 From Bulletin 1-SECM-03

(Rev. 2/03) All information subject to change without notice.

6SE497 0207 Copyright © 2003 DETROIT DIESEL CORPORATION

DDEC III/IV SINGLE ECM TROUBLESHOOTING GUIDE

48.1 DESCRIPTION OF FLASH CODE 48

Flash Code 48 indicates that the ECM has detected that the Fuel Pressure has dropped below a programmed limit. This condition is normally associated with a restriction in the fuel supply system:

Plugged fuel filter

Low fuel supply

NOTE:

Not all engines use a fuel pressure sensor, see Figure 48-1.

For gas engines, code 48 indicates that the air inlet pressure has dropped below a calibration limit.

Flash Code 48 is also used to identify the EGR Delta-Pressure, or EGR temperature is below programmed limits. This condition is typically due to:

EGR valve not opening completely

EGR valve not opening at all – leaking CAC.

Leaking EGR piping/hoses.

Flash Code 48 also indicates the exhaust gas temperature fell below calibrated limits, or EGR

Delta-Pressure fell below calibrated limits. Possible causes include:

EGR valve not opening

EGR valve not opening fully

Leaking CAC

Flash Code 48 also indicates the TCI (Turbo Compressor Inlet) or TCO (Turbo Compressor

Outlet) temperature fell below the calibrated limits. Possible causes include:

Leaking CAC

Leaking inlet piping

EGR valve not opening properly

All information subject to change without notice.

(Rev. 2/03)

6SE497 0207 Copyright © 2003 DETROIT DIESEL CORPORATION

From Bulletin 1-SECM-03 48-3

48.2

SAE J1587 EQUIVALENT CODE FOR FLASH CODE 48

48.2 SAE J1587 EQUIVALENT CODE FOR FLASH CODE 48

The SAE J1587 equivalent code for Flash Code 48 is p 094/1, fuel pressure low.

The SAE J1587 equivalent code for Flash Code 48 is p 106/1, air inlet pressure low. (Gas-fueled engines)

The SAE J1587 equivalent code for Flash Code 48 is p 412/1, EGR temperature low (35.00

ECM software and higher).

The SAE J1587 equivalent code for Flash Code 48 is p 154/1, EGR temperature low (32.xx

ECM software and lower).

The SAE J1587 equivalent code for Flash Code 48 is p 411/1, EGR Delta-Pressure low (35.00

ECM software and higher).

The SAE J1587 equivalent code for Flash Code 48 is p 155/1, EGR Delta-Pressure low (32.xx

ECM software and lower).

The SAE J1587 equivalent code for Flash Code 48 is p 351/1, TCI temperature below range.

The SAE J1587 equivalent code for Flash Code 48 is p 404/1, TCO temperature below range.

48-4 From Bulletin 1-SECM-03

(Rev. 2/03) All information subject to change without notice.

6SE497 0207 Copyright © 2003 DETROIT DIESEL CORPORATION

DDEC III/IV SINGLE ECM TROUBLESHOOTING GUIDE

48.3 TROUBLESHOOTING FLASH CODE 48

Fuel Pressure code is logged as a result of a mechanical fault. Check for reasons for low fuel pressure. Refer to appropriate service manual, section 5.

This (Gas-fueled engine) code is logged as a result of a mechanical fault. Check for reasons for low air inlet pressure. Refer to appropriate service manual, section 6.

For all EGR related codes, always perform the basic checks in (EGR-1) for Series 50 engines; refer to section 10.16. For Series 60 engines, refer to section 10.18.

Then, perform the following steps to troubleshoot code 48:

48.3.1

Check for Other Codes

Perform the following steps to check for other codes:

1. Turn ignition ON.

2. Plug in DT.

3. Read active codes.

[a] If codes 63 (s 060) and/or 31 (s 52) display, service those codes first.

[b]

If codes 63 (s 060) and/or 31 (s 52) do not display, refer to section 48.3.2.

All information subject to change without notice.

(Rev. 2/03)

6SE497 0207 Copyright © 2003 DETROIT DIESEL CORPORATION

From Bulletin 1-SECM-03 48-5

48.3

TROUBLESHOOTING FLASH CODE 48

48.3.2

Vehicle Air Test

Perform the following steps to check the vehicle air test. The vehicle air test should have been performed during EGR–1 on a Series 50 engine; refer to section 10.16. On a Series 60 engine, refer to section 10.18. If the test was not performed, refer to proper section and perform all steps.

1. If the vehicle air system failed the test, resolve low vehicle air pressure.

2. If the vehicle air system passed the test, replace the EGR valve and refer to section 48.3.3

for verification of repairs.

3. No additional DDEC troubleshooting is recommended for these six codes. Check all

Basic Checks and then contact Technical Service for instructions, providing a snapshot and code logging details.

48.3.3

Verify Repairs

Perform these steps to verify repairs to the vehicle air system:

1. Connect all connectors.

2. Start engine.

3. Perform road test.

4. Has the fault returned?

[a] If the code is logged, review this section to find the error. If the fault returns after review, try a test ECM or contact Detroit Diesel Technical Services.

[b] If no codes are logged, troubleshooting is complete.

48-6 From Bulletin 1-SECM-03

(Rev. 2/03) All information subject to change without notice.

6SE497 0207 Copyright © 2003 DETROIT DIESEL CORPORATION