AT–36 A750E AUTOMATIC TRANSMISSION – AUTOMATIC TRANSMISSION SYSTEM DIAGNOSIS SYSTEM 1. FI00534E02 Intelligent Tester CAN VIM DLC3 AT H102157E03 DESCRIPTION (a) When troubleshooting On-Board Diagnostic (OBD II) vehicles, the vehicle must be connected to the intelligent tester (complying with SAE J1987). Various data output from the vehicle's ECM can then be read. (b) OBD II regulations require that the vehicle's onboard computer illuminate the Malfunction Indicator Lamp (MIL) on the instrument panel when the computer detects a malfunction in: 1. The emission control system/components 2. The power train control components (which affect vehicle emissions) 3. The computer In addition, the applicable Diagnostic Trouble Codes (DTCs) prescribed by SAE J2012 are recorded in the ECM memory. If the malfunction does not recur in 3 consecutive trips, the MIL turns off automatically but the DTCs remain recorded in the ECM memory. (c) To check DTCs, connect the intelligent tester to the Data Link Connector 3 (DLC3) of the vehicle. The intelligent tester displays DTCs, the freeze frame data and a variety of the engine data. The DTCs and freeze frame data can be erased with the intelligent tester (See page AT-33). (d) In order to enhance OBD function on vehicles and develop the Off-Board diagnosis system, CAN communication has been introduced in this system (CAN: Controller Area Network). It minimizes the gap between technician skills and vehicle technology. CAN is a network, which uses a pair of data transmission lines, spanning multiple computers and sensors. It allows high speed communication between the systems and simplification of the wire harness connection. Since this system is equipped with CAN communication, CAN VIM (VIM: Vehicle Interface Module) connecting with intelligent tester is necessary to display any information from the ECM on the tester. (Also communication between the intelligent tester and the ECM uses a CAN communication signal.) When confirming DTCs and any data of the ECM, connect the CAN VIM between the DLC3 and the intelligent tester. A750E AUTOMATIC TRANSMISSION – AUTOMATIC TRANSMISSION SYSTEM 2. 3. 4. 0.5 0.5 A092901E12 5. DLC3 CG SG NORMAL MODE AND CHECK MODE (a) The diagnosis system operates in "normal mode" during normal vehicle use. In normal mode, "2 trip detection logic" is used to ensure accurate detection of malfunctions. "Check mode" is also available to technicians as an option. In check mode, "1 trip detection logic" is used for simulating malfunction symptoms and increasing the system's ability to detect malfunctions, including intermittent malfunctions. 2 TRIP DETECTION LOGIC (a) When a malfunction is first detected, the malfunction is temporarily stored in the ECM memory (1st trip). If the ignition switch is turned OFF and then ON again, and the same malfunction is detected again, the MIL will illuminate. FREEZE FRAME DATA (a) Freeze frame data records the engine conditions (fuel system, calculated load, engine coolant temperature, fuel trim, engine speed, vehicle speed, etc.) when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was Lean or Rich, and other data from the time the malfunction occurred. (b) The ECM records engine conditions in the form of freeze frame data every 0.5 seconds. Using the intelligent tester, five separate sets of freeze frame data, including the data values at the time when the DTC was set, can be checked. • 3 data sets before the DTC was set • 1 data set when the DTC was set • 1 data set after the DTC was set These data sets can be used to simulate the condition of the vehicle around the time the occurrence of the malfunction. The data may assist in identifying of the cause of the malfunction, and in judging whether it was temporary or not. (Seconds) 0.5 AT–37 CANH SIL DATA LINK CONNECTOR 3 (DLC3) (a) The vehicle's ECM uses the ISO 15765-4 communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format. 1 2 3 4 5 6 7 8 9 10 11 1213141516 CANL Symbols (Terminal No.) BAT A082779E81 Terminal Description Condition Specified Condition SIL (7) - SG (5) Bus "+" line During transmission Pulse generation CG (4) - Body ground Chassis ground Always Below 1 Ω AT AT–38 AT A750E AUTOMATIC TRANSMISSION – AUTOMATIC TRANSMISSION SYSTEM Symbols (Terminal No.) Terminal Description Condition Specified Condition SG (5) - Body ground Signal ground Always Below 1 Ω BAT (16) - Body ground Battery positive Always CANH (6) - CANL (14) CAN bus line CANH (6) - CG (4) HIGH-level CAN bus line Ignition switch OFF* 200 Ω or higher CANL (14) - CG (4) LOW-level CAN bus line Ignition switch OFF* 200 Ω or higher CANH (6) - BAT (16) HIGH-level CAN bus line Ignition switch OFF* 6 kΩ or higher CANL (14) - BAT (16) LOW-level CAN bus line Ignition switch OFF* 6 kΩ or higher 6. 7. 8. Ignition switch 11 to 14 V OFF* 54 to 69 Ω NOTICE: * : Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches or the doors. If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector. HINT: Connect the cable of the intelligent tester to the DLC3, turn the ignition switch to the ON position and attempt to use the intelligent tester. If the screen displays UNABLE TO CONNECT TO VEHICLE, a problem exists in the vehicle side or the tester side. If the communication is normal when the tester is connected to another vehicle, inspect the DLC3 on the original vehicle. If the communication is still impossible when the tester is connected to another vehicle, the problem is probably in the tester itself. Consult the Service Department listed in the tester's instruction manual. CHECK BATTERY VOLTAGE Standard voltage: 11 to 14 V (a) If the voltage is below 11 V, replace the battery before proceeding. CHECK MIL (a) Check that the MIL illuminates when turning the ignition switch ON. If the MIL does not illuminate, there is a problem in the MIL circuit (See page ES-404). (b) When the engine is started, the MIL should turn off. ALL READINESS (a) For this vehicle, using the intelligent tester allows readiness codes corresponding to all DTCs to be read. When diagnosis (normal or malfunctioning) has been completed, readiness codes are set. Enter the following menus: ENHANCED OBD II / MONITOR INFO on the intelligent tester.
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