Diagnostic Flow

TCC diagnosis should be performed in the following order:

See TROUBLE SHOOTING .
See RETRIEVING TROUBLE CODES or DISPLAYING TROUBLE CODES under appropriate TESTING & DIAGNOSIS.
Verify TCC system fault.
See TORQUE CONVERTER CLUTCH CHARTS (TRUCKS) .
See DIAGNOSTIC FLOW CHARTS (CARS) or DIAGNOSTIC CODE CHARTS (TRUCKS) .

NOTE: This article contains test charts that are part of General Motors Computerized Engine Controls. Only those charts required to test Torque Converter Clutch (TCC) system and related circuits are included. Other diagnostic codes may appear while performing TCC electrical diagnosis. See appropriate article in the ENGINE PERFORMANCE section for complete information on General Motors Computerized Engine Control systems.