NO.16 JUDDER UPON TORQUE CONVERTER CLUTCH (TCC) OPERATION [FN4A-EL]


16	Judder upon torque converter clutch (TCC) operation
DESCRIPTION	• Vehicle jolts when TCC is engaged.
POSSIBLE CAUSE	• Poor TCC engagement due to either slippage because the TCC is stuck or the line pressure is low 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. Torque converter clutch piston slipped, burned • Line pressure high • Shift solenoid A malfunction • Control valve body malfunction • Body GND malfunction • Pressure control solenoid malfunction 2. Signal malfunction • Vehicle speed sensor malfunction • Sensor GND malfunction • TFT sensor malfunction • TP sensor malfunction or mis-adjustment • Input/turbine speed sensor malfunction 3. Torque converter malfunction Note • Before following troubleshooting steps, make sure that Automatic Transaxle On-Board Diagnostic and Automatic Transaxle Basic Inspection are conducted.


STEP	INSPECTION		ACTION
1	• Check the value at the following PIDs using the WDS or equivalent. (See PCM INSPECTION [WITHOUT WU-TWC].) (See PCM INSPECTION [WITH WU-TWC].) - TSS • Are PID values normal?	Yes	Go to next step.
1		No	Repair or replace any defective parts.
2	• Disconnect PCM. • Is resistance between ground terminal at PCM connector and body ground less than 5.0 ohms?	Yes	Go to next step.
2		No	Repair open ground circuit.
3	• Check resistance between shift solenoid A control circuit at PCM connector and control valve body connector. • Check resistance between shift solenoid A circuit at PCM connector and control valve body connector. • Are the resistance less than 5.0 ohms?	Yes	Go to next step.
3		No	Repair shift solenoid A circuit.
4	• Inspect Shift solenoid. (See SOLENOID VALVE INSPECTION [FN4A-EL].) Is the solenoid valve operating properly?	Yes	Go to next step.
4		No	Overhaul control valve body and repair or replace any defective parts. (See ATX workshop manual (FN4A-EL) [1623-10-98E].) If problem remains, overhaul transaxle and repair or replace any defective parts. (See ATX workshop manual (FN4A-EL) [1623-10-98E].)
5	• Check LPS PID value. (See PCM INSPECTION [WITHOUT WU-TWC].) (See PCM INSPECTION [WITH WU-TWC].) • Is LPS PID value normal?	Yes	Overhaul control valve body and repair or replace any defective parts. (See ATX workshop manual (FN4A-EL) [1623-10-98E].) If problem remains, overhaul transaxle and repair or replace any defective parts. (See ATX workshop manual (FN4A-EL) [1623-10-98E].)
5		No	Replace PCM.
6	• Verify test results. - If normal, return to diagnostic index to service any additional symptoms. - If malfunction remains, inspect related Service Information and perform repair or diagnosis. • If vehicle repaired, troubleshooting completed. • If vehicle not repaired or additional diagnostic information not available, replace PCM.