Trouble Code Definition

PCM/TCM TROUBLE CODE DEFINITION

Code No.

Circuit Affected

12 ⁽¹⁾

No RPM Reference Pulse

Coolant Temperature High

Coolant Temperature Low

Throttle Position Switch Voltage High

Throttle Position Switch Voltage Low

Output Speed Sensor Circuit

Pressure Switch Manifold Problem

System Voltage Too High

⁽²⁾ TCC Problem

Transmission Temperature High

Transmission Temperature Low

Overdrive Ratio Error Problem

Force Motor Current Problem

System Voltage Too Low

Shift Solenoid "B" Circuit Error

Shift Solenoid "A" Circuit Error

TCC Solenoid Circuit Error

Undefined Ratio Error Problem

Low Ratio Error Problem

High Ratio Error Problem

⁽¹⁾	Display of a Code 12 is normal when no reference pulses are received by control module (engine not running).

⁽²⁾	Code 39 indicates TCC problem may be present. For complete information, see GM TORQUE CONVERTER CLUTCH article.

NOTE: Only transmission-related trouble codes are listed. If other trouble codes are present, see appropriate article in the ENGINE PERFORMANCE section.