Chart C-8A, Torque Converter Clutch Functional Check - 1992 3.8L PFI (VIN 1): Notes

Fig 1: Chart C-8A, TCC Circuit Diagram (1992 3.8L PFI VIN 1)

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. PWN solenoid varies hydraulic pressure to make locking and unlocking of TCC smoother. TCC will engage under the following conditions:

• Engine is warmed up.
• Vehicle speed above a calibrated value of about 28 MPH.
• Throttle position not changing, indicating a steady speed.
• Brake switch is closed.
  NOTE: Test numbers refer to test numbers on diagnostic chart.
  1. This test determines whether fault is caused by a bad solenoid or control circuit.
  2. This test checks availability of voltage on circuit No. 420.
  3. This test checks PCM's capability to pulse PWM solenoid on and off.
  4. Electrical circuits have checked out okay. Refer to appropriate AUTO TRANS DIAGNOSIS article for hydraulic and mechanical diagnosis.