NO.12 TORQUE CONVERTER CLUTCH (TCC) NON-OPERATION


12	Torque converter clutch (TCC) non-operation
DESCRIPTION	• TCC does not operate when vehicle reaches TCC operation range.
POSSIBLE CAUSE	• Basically, the TCC does not operate when the fail-safe is operating. Verify the DTC first. Caution • If the TCC is stuck, inspect it. In addition, inspect the oil cooler for foreign particles which may have mixed in with the ATF. 1. TCC burnt (1) Input sensor system malfunction • Transaxle fluid temperature sensor • Vehicle speed sensor • Input/turbine speed sensor • Sensor GND (2) Output solenoid valve system malfunction (Sticking) • Shift solenoid E malfunction • Shift solenoid A malfunction (3) Control valve body malfunction system (Poor operation, stuck) • TCC hydraulic pressure system 2. TP sensor malfunction (Not operating linear) 3. Input/turbine speed sensor or vehicle speed sensor malfunction 4. Brake switch malfunction (Always ON) 5. ECT sensor malfunction Note • Before following the troubleshooting steps, make sure that the Automatic Transaxle On-Board Diagnostic and Automatic Transaxle Basic Inspection are conducted.


STEP	INSPECTION		ACTION
1	With the ignition switch at the ON position, does the gear position indicator light indication correspond to the selector lever position?	Yes	Go to the next step.
1		No	Go to No.27 "GEAR POSITION INDICATOR LIGHT DOES NOT ILLUMINATE IN M RANGE" or No.28 "GEAR POSITION INDICATOR LIGHT ILLUMINATES IN D RANGE OR P, N, R POSITIONS"
2	Inspect the value at the following PCM PIDs using the WDS or equivalent. (See PCM INSPECTION [ZY, Z6].) (See PCM INSPECTION [LF, L3].) • TP • OSS • TSS Are the PID values normal?	Yes	Go to the next step.
2		No	Repair or replace any malfunctioning parts.
3	Disconnect the PCM connector. Is the resistance between the ground terminal at the PCM connector and the body ground less than 5.0 ohms?	Yes	Go to the next step.
3		No	Repair the open ground circuit.
4	Inspect the resistance between shift solenoid A and E control circuit at the PCM connector and control valve body connector. Inspect resistance between shift solenoid A and E circuit at the PCM connector and control valve body connector. Are the resistances less than 5.0 ohms?	Yes	Go to the next step.
4		No	Repair the shift solenoid A or E control. Reconnect the PCM.
5	Inspect the shift solenoid A and E. (See SOLENOID VALVE INSPECTION.) Are the shift solenoids operating properly?	Yes	Replace the PCM.
5		No	Overhaul the control valve body and repair or replace any malfunctioning parts. (See ATX workshop manual (FN4A-EL).) If any problem remains, overhaul the transaxle and repair or replace any malfunctioning parts. (See ATX workshop manual (FN4A-EL).)
6	• Verify the test results. - If normal, return to the diagnostic index to service any additional symptoms. - If the malfunction remains, inspect the related Service information and perform repair or diagnosis. • If the vehicle is repaired, troubleshooting is completed. • If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM.