GM Service Manual Online
For 1990-2009 cars only

No Torque Converter Clutch (TCC) Apply

Checks

Causes

Valve Body Assembly

    • Regulator apply valve side loading
    • Stuck converter clutch valve
    • TCC apply valve stuck closed (debris in bore)
    • TCC/PWM solenoid broken/cracked
    • Turbine shaft O-ring omitted
    • TCC/PWM solenoid leaking

Input Housing and Turbine Shaft Assembly

    • Turbine shaft hole not drilled to full depth
    • Scratched turbine shaft journals
    • Turbine shaft O-ring omitted/damaged
    • Turbine shaft retainer and ball assembly restricted or damaged

Electrical

    • 12 volts not supplied to transmission
    • Outside electrical connector damaged
    • Inside electrical connector damaged
    • Wire harness damaged
    • TCC solenoid damaged
    • Electrical short (pinched wire)
    • TCC solenoid not grounded

Torque Converter Clutch

Internal damage (blue or distorted)

Oil Pump Assembly

    • TCC outer spring cocked
    • Orifice cup plug restricted or damaged
    • Pump to case gasket mispositioned
    • Converter clutch valve retaining ring mispositioned
    • Converter clutch valve stuck or assembled backwards

Transmission Fluid Pressure Manual Valve Position Switch

    • Contamination
    • Damaged seals

Solenoid Screen

Blocked

TCC Solenoid Valve

Internal damage

Engine Speed Sensor

Internal damage

Engine Coolant Temperature Sensor

Internal damage

Automatic Transmission Fluid Temperature Sensor

Internal damage

Brake Switch

Internal damage

VCM

Internal damage

TCC PWM Solenoid

Internal damage