Chart C-8 Torque Converter Clutch - 3.1L Vans: Notes

Fig 1: Chart C-8 TCC Circuit Diagram (3.1L Vans)

Courtesy of GENERAL MOTORS CORP.

Fused battery voltage is supplied to TCC solenoid through TCC brake switch and 3rd gear apply switch. ECM will engage TCC by grounding circuit No. 422 to energize solenoid. TCC will engage when:

• Vehicle speed is above 30 MPH.
• Engine is at normal operating temperature.
• Throttle position not changing, indicating a steady speed.
• Brake switch and 3rd gear switch are closed.
  NOTE: Test numbers refer to test numbers in diagnostic chart.
  1. If test light does not light, 3rd gear apply switch is open.
  2. At 25 MPH, 3rd gear apply switch should close. Test light should glow and confirm battery voltage exist and closed brake switch.
  3. Grounding diagnostic terminal with ignition switch on and engine off, should energize TCC solenoid by grounding circuit No. 422. This test checks ability of ECM to supply a ground to the TCC solenoid. Test light will glow if connected from 12 volts to ALDL terminal "F" when circuit No. 422 is grounded.