Chart C-8A, 3T40 Torque Converter Clutch, 3.3L PFI N Body: Notes

Fig 1: Chart C-8A, 3T40 TCC Circuit Diagram (3.3L PFI N Body)

Courtesy of GENERAL MOTORS CORP.

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

TCC will engage under the following conditions:

• Engine is warmed up.
• Vehicle speed above a calibrated value of about 33 MPH.
• Throttle position not changing, indicating a steady speed.
• Transmission 3rd gear switch closed.
• Brake switch closed.
• TCC apply switch closed.
  NOTE: Test numbers refer to test numbers on diagnostic chart.
  1. This test checks gage fuse and brake switch.
  2. this test checks ECM for proper operation.
  3. This test checks internal switches in transmission.