Fault Diagnosis
Features a fail-safe mechanism that prevents dangerous situations from developing in the event of a transaxle failure. The limp home mode engages if the transaxle malfunctions. In this mode, the transaxle operates at a minimal functionality level, making it possible for the vehicle to reach a service center. Fail-Safe: Prevents dangerous situations from developing in the event of a malfunction. Limp Home: Maintains minimal functionality (*) in the event of a malfunction, making it possible for the vehicle to reach a service center. (*) Minimal Functionality: Drive (fixed gear setting), Reverse, and Neutral
Self-Diagnosis
TCM is in constant communication with the control system's components (sensors and solenoids). If an abnormal signal is received for longer than the predefined duration, TCM recognizes a fault, stores the fault code in memory, and then sends out a fault signal through the self-diagnosis terminal. Such fault codes are the ignition switch is turned off, the battery is disconnected, or the TCM connector is disconnected.
Note. Disconnecting a sensor or an actuator connector while the ignition switch is in the "On" position generates a diagnostic trouble code (DTC) and commits the code to memory. In such event, disconnecting the battery will not clear the fault diagnosis memory. The diagnosis tool must be used to clear the fault diagnosis memory. Before removing or installing any part, read the diagnostic trouble codes and then disconnect the battery negative (-) terminal. Before disconnecting the cable from battery terminal, turn the ignition switch to OFF. Removal or connection of the battery cable during engine operation or while the ignition switch is ON could cause damage to the TCM When checking the generator for the charging state, do not disconnect the battery '+' terminal to prevent the ECM from damage due to the voltage. When charging the battery with the external charger, disconnect the vehicle side battery terminals to prevent damage to the TCM.
Inspection Procedure (Using the GDS)
Note. When battery voltage is excessively low, diagnostic trouble codes can not be read. Be sure to check the battery for voltage and the charging system before starting the test. Diagnosis memory is erased if the battery or the TCM connector is disconnected. Do not disconnect the battery before the diagnostic trouble codes (DTC) are completely read and recorded.
- Turn OFF the ignition switch.
- Connect the GDS to the data link connector on the lower crash pad.
- Turn ON the ignition switch.
- Use the GDS to check the diagnostic trouble code.
- Repair the faulty part from the diagnosis chart.
- Erase the diagnostic trouble code.
- Disconnect the GDS.
| No. | Symptom | Expectation cause | Fault diagnosis list | Check point |
|---|---|---|---|---|
| 1 | Automatic transaxle delay | Clutch/Brake damage Oil pressure control faulty Oil pressure supply faulty | Asynchronous error | Clutch/Brake Solenoid valve, Valve body Electric Oil Pump (EOP) Mechanical Oil Pump (MOP) Automatic transaxle fluid cleanliness (Debris) Automatic transaxle fluid level |
| 2 | Automatic transaxle or driveline vibration | Clutch/Brake damage Oil pressure control faulty Oil pressure supply faulty Automatic transaxle mounting faulty Speed sensor faulty Automatic transaxle harness faulty Damage to the vehicle connectors and wiring | Asynchronous errors Speed sensor errors | Clutch/Brake Solenoid valve, Valve body Electric Oil Pump (EOP) Mechanical Oil Pump (MOP) Automatic transaxle fluid cleanliness (Debris) Automatic transaxle fluid level Speed sensor and connector Automatic transaxle harness and connector Vehicle connectors and wiring |
| 3 | Fixed gear (Shift not possible) | Solenoid valve faulty TCM S/W reprogram | Solenoid valve errors TCM checksum error Asynchronous error | Clutch/Brake Solenoid valve, Valve body Electric Oil Pump (EOP) Mechanical Oil Pump (MOP) Automatic transaxle fluid cleanliness (Debris) Automatic transaxle fluid level Speed sensor and connector Automatic transaxle harness and connector Vehicle connectors and wiring |
| 4 | Vehicle moves, but drivetrain in limp mode | Inhibitor switch faulty Oil pressure supply faulty | Inhibitor switch faulty Electric Oil Pump (EOP) faulty Oil Pump Unit (OPU) faulty Electric Oil Pump (EOP) Relay faulty | Inhibitor switch and wiring Electric Oil Pump (EOP) (Hall IC, 3P Power Control Circuit) Oil Pump Unit (OPU) Electric Oil Pump (EOP) relay Vehicle connectors and wiring Power |
| 5 | HEV not driving (E/C limp home) | CAN communication faulty Engine clutch solenoid valve faulty HSG, Motor, Battery etc. part faulty | CAN communication faulty Engine clutch solenoid valve faulty | CAN communication line Controller Power line Engine clutch solenoid valve High voltage battery etc. faulty |
| 6 | Poor acceleration | Oil pressure supply faulty | Electric Oil Pump (EOP)/Oil Pump Unit faulty Electric Oil Pump (EOP) relay faulty Power line faulty | Electric Oil Pump (EOP) (Hall IC, 3P Power Control Circuit) Oil Pump Unit (OPU) Electric Oil Pump(EOP) Relay Vehicle connectors and wiring Power |