Chart C-8A, Torque Converter Clutch - 3.1L PFI F Body: Notes

Fig 1: Clutch C-8B, TCC Circuit Diagram (3.1L F Body)

Courtesy of GENERAL MOTORS CORP.

When solenoid coil is activated, TCC is applied which results in a straight through mechanical coupling from engine to wheels. When solenoid coil is deactivated, TCC is released which allows torque converter to operate in conventional manner. ECM turns on TCC when engine coolant temperature is greater than 149°F (65°C), TPS not changing and vehicle speed is greater than a specified value.

1. When test light is connected from ALDL terminal "F" to ground, a test light on indicates battery voltage is okay and TCC solenoid is disengaged.
2. When diagnostic terminal is grounded, ECM should energize TCC solenoid and test light should go out.