NO.28 TORQUE CONVERTER CLUTCH (TCC): ALWAYS APPLIED/ENGINE MAY STALL[LA4AX-EL (CD4E)]

id0503a2806400

28

Torque converter clutch (TCC): Always applied/engine may stall

POSSIBLE CAUSE

•  Powertrain control system malfunction

•  Control valve body malfunction

•  Oil pump malfunction

•  Torque converter component malfunction

•  Transaxle case malfunction

28	Torque converter clutch (TCC): Always applied/engine may stall
POSSIBLE CAUSE	• Powertrain control system malfunction • Control valve body malfunction • Oil pump malfunction • Torque converter component malfunction • Transaxle case malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	Powertrain control system • Are there any malfunctions with the following? ― Electrical input/output ― Vehicle wiring harness ― PCM ― Transaxle fluid temperature (TFT) sensor ― TCC solenoid	Yes	Perform OBD test Perform DTC troubleshooting (See AUTOMATIC TRANSAXLE ON-BOARD DIAGNOSTIC FUNCTION[LA4AX-EL (CD4E)].)
1		No	Go to the next step
2	Control valve body • Do any of the following malfunctions exist? ― Bolts are not tightened to the specification ― Gaskets are damaged ― Bypass clutch control valve and plunger (always applied), converter regulator valve are stuck, damaged, or misassembled ― Separator plates are damaged or blocked ― Converter is not applied in first gear or reverse gear ― TCC solenoid malfunction ― Pressure tap plate/gasket are damaged ― Hydraulic passages are damaged	Yes	Service if necessary
2		No	Go to the next step
3	Oil pump • Do any of the following malfunctions exist? ― Bolts are not tightened to the specification ― Gaskets are damaged ― Pump support seal ring #1 is damaged, missing, misassembled	Yes	Service if necessary
3		No	Go to the next step
4	Torque converter component • Do either of the following malfunctions exist? ― Internal seals are damaged ― Piston plate is damaged or stuck to cover	Yes	Service if necessary
4		No	Go to the next step
5	Transaxle case • Does the following problem exist? ― Porosity/cross leaks in CBY circuit	Yes	Service if necessary
5		No	The problem is fixed
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.