Chart C-8A Torque Converter Clutch (TCC) Relay System Check

Diagnostic Chart:

Electrical Schematic:

CIRCUIT DESCRIPTION
Based on signals from the Throttle Position (TP) sensor (throttle opening), the ignition coil, and Engine Coolant Temperature (ECT) sensor, the Engine Control Module (ECM) will provide the ground for the Torque Converter Clutch (TCC) circuit. The TCC (lock-up) solenoid, under control of the stoplamp switch, automatic transmission fluid pressure switch, and the TCC relay, opens and closes the automatic transmission fluid passage to lock and unlock the torque converter clutch. For further description of operation of TCC, refer to Transmission and Drivetrain / Automatic Transmission / Transaxle / Torque Converter Clutch. Description and Operation

CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. Checks to see if voltage is supplied to ECM.
2. Checks for voltage at transmission.
3. Checks for an open or short to ground in WHT/YEL wire.
4. Checks for an open in WHT wire.
5. Checks for a faulty TCC relay or an open in BLU/BLK wire.
6. Checks for a faulty TCC relay.
7. Checks for an open in WHT/RED wire.
8. Checks for power to the stoplamp switch, or a faulty stop lamp switch.

DIAGNOSTIC AIDS
The Torque Converter Clutch will operate only under the following conditions:
1. Throttle valve opening is greater than 7 degrees and less than 62 degrees.
2. Engine coolant temperature is greater than 6O°C (14O°F).
3. Brake pedal released (switch closed).
4. Automatic transmission fluid pressure is normal below 415 kPa (60 psi).

INTERMITTENT MALFUNCTIONS
An intermittent malfunction may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connections before component replacement.