Torque Converter Clutch: Testing and Inspection

Chart C-8B:

Converter Clutch Schematic:

CIRCUIT DESCRIPTION
The transmission converter clutch is activated by a Torque Converter Clutch (TCC) solenoid located inside the transmission pan. The solenoid is supplied voltage by the ignition and the Electronic Control Module (ECM) completes the ground to energize the solenoid.

TEST DESCRIPTION
Numbers below refer to circled numbers on the diagnostic chart:

1. Checks for complete circuit from ignition through TCC solenoid to ALCL TCC test terminal. Normally the light should be "ON" if circuit is not grounded or open.

2. Checks to see if ECM completes ground to energize TCC solenoid. Light should go "OUT".

3. This increases throttle opening to increase Throttle Position Sensor (TPS) output. If TPS output is too low, the clutch won't apply. On some applications, running free doesn't require enough throttle opening to allow the transmission to shift.

4. Checks for ground in circuit to ECM terminal "P". Normally light should be "OFF".

5. Checks for open in wire to transmission from TCC test point or open in TCC solenoid connections or solenoid. If wiring is complete test light should be "ON".