Troubleshooting

Troubleshooting

Diagnostic Trouble Code Troubleshooting

Has a fail-safe mechanism that prevents hazardous situations from occurring when the transmission malfunctions. Limp home mode is activated if the transmission is faulty. In this mode the transmission operates at a minimum functional level, allowing the vehicle to reach a service center. Fail-safe: prevents hazardous situations from developing in case of a malfunction. Limp home: maintains minimum functionality (*) in case of a malfunction, allowing the vehicle to reach a service center. (*) Minimum functionality: Drive (fixed gear), Reverse and Neutral

Self-Diagnosis

The TCM is in constant communication with the control system components (sensors and solenoids). If an abnormal signal is received for longer than the specified time, the TCM detects a malfunction, stores the DTC in memory, and then sends a malfunction signal via the self-diagnosis terminal. Such DTCs are erased when the ignition switch is OFF, the battery is disconnected, or the TCM connector is disconnected.

Disconnecting a sensor or actuator connector while the ignition switch is in the ON position causes a diagnostic trouble code (DTC) to be set and stored in memory. In this case, disconnecting the battery will not clear the diagnostic trouble code memory. Use a diagnostic tool to clear the diagnostic trouble code memory. Before removing or installing any component, read the diagnostic trouble codes, then disconnect the negative (-) battery terminal. Before disconnecting the battery cable, turn the ignition switch to the OFF position. Removing or connecting the battery cable while the engine is running or the ignition is ON may damage the TCM. When checking the charging system of the generator, do not disconnect the positive (+) battery terminal, to prevent damage to the ECM from voltage surges. When charging the battery with an external charger, disconnect the battery terminals from the vehicle side to avoid damaging the TCM.

Inspection Procedure (Using GDS)

When battery voltage is too low, diagnostic trouble codes cannot be read. Be sure to check the battery voltage and the charging system before starting the test. Diagnostic memory is erased if the battery or the TCM connector is disconnected. Do not disconnect the battery until the diagnostic trouble codes (DTCs) have been completely read and recorded.

1. 1
   Turn the ignition off.
2. 2
   Connect the GDS to the data link connector under the lower crash pad.
3. 3
   Turn the ignition on.
4. 4
   Use the GDS to check the diagnostic trouble code.
5. 5
   Repair the faulty part according to the diagnostic flow chart.
6. 6
   Erase the diagnostic trouble code.
7. 7
   Disconnect the GDS.

No.	Symptom	Waiting cause	Troubleshooting list	Checkpoint
1	Automatic transmission delay	• Clutch/brake damage • Faulty oil pressure control • Faulty oil pressure supply	• Asynchronous error	• Clutch/brake • Solenoid valve, valve body • Electric oil pump (EOP) • Mechanical oil pump (MOP) • Automatic transmission fluid cleanliness (debris) • Automatic transmission fluid level
2	Automatic transmission or transaxle vibration	• Clutch/brake damage • Faulty oil pressure control • Faulty oil pressure supply • Faulty automatic transmission mounting • Faulty speed sensor • Faulty automatic transmission wire harness • Damaged vehicle connectors and wiring	• Asynchronous errors • Speed sensor errors	• Clutch/brake • Solenoid valve, valve body • Electric oil pump (EOP) • Mechanical oil pump (MOP) • Automatic transmission fluid cleanliness (debris) • Automatic transmission fluid level • Speed sensor and connector • Automatic transmission wire harness and connector • Vehicle connectors and wiring
3	Fixed gear (Shifting not possible)	• Solenoid valve faulty • TCM S/W reprogramming	• Solenoid valve errors • TCM checksum error • Asynchronous error	• Clutch/brake • Solenoid valve, valve body • Electric oil pump (EOP) • Mechanical oil pump (MOP) • Automatic transmission fluid cleanliness (debris) • Automatic transmission fluid level • Speed sensor and connector • Automatic transmission wire harness and connector • Vehicle connectors and wiring
4	Vehicle moves, but transmission is in fail-safe mode	• Inhibitor switch faulty • Faulty oil pressure supply	• 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, 3-wire power control circuit) • Oil pump unit (OPU) • Electric oil pump (EOP) relay • Vehicle connectors and wiring • Power supply
5	HEV not driving (E/C limp home mode)	• CAN communication error • Engine clutch solenoid faulty • HSG, engine, battery, etc. faulty	• CAN communication error • Engine clutch solenoid faulty	• CAN communication line • Controller • Power line • Engine clutch solenoid • High-voltage battery faulty, etc.
6	Poor acceleration	• Faulty oil pressure supply	• Electric oil pump (EOP) / oil pump unit faulty • Electric oil pump (EOP) relay faulty • Power line faulty	• Electric oil pump (EOP) (Hall IC, 3-wire power control circuit) • Oil pump unit (OPU) • Electric oil pump (EOP) relay • Vehicle connectors and wiring • Power supply