Section 2 (Engine Controls - Tests W/Codes - Transmission)
WARNING: This page does not describe the selected car, but rather 23 other vehicles, including the 1991 GMC Vandura Special, 1991 GMC Vandura, 1991 GMC Value Van, 1991 GMC Suburban, and 1991 GMC Rally Camper Special. However, it is still accessible from the selected car via links, so may be relevant.
- Introduction
- Self-Diagnostic System
- Trouble Code Charts
- Notes
- Code 28, Pressure Switch Manifold Fault
- Code 39, Torque Converter Clutch Stuck "Off" Position
- Code 53, System Voltage High
- Code 58, Transmission Temp Sensor CKT (High Temp Indicated)
- Code 59, Transmission Temp Sensor CKT (Low Temp Indicated)
- Code 68, Overdrive Ratio Error
- Code 73, Force Motor Current (Current Error)
- Code 75, System Voltage Low
- Code 81, QDM Fault (Solenoid "B")
- Code 82, QDM Fault (Solenoid "A")
- Code 83, TCC QDM Fault
- Code 85, Undefined Ratio
- Code 86, Shift Solenoid "B" Stuck "On"
- Code 87, Shift Solenoid "B" Stuck "Off"
- Component Check Charts
- Notes
- Output Speed Sensor CKT Check (2WD - Except "C" & "K" Series)
- Output Speed Sensor Circuit Check (2WD - "C" & "K" Series)
- Output Speed Sensor Circuit Check (4WD Vehicles)
- Input Speed Sensor Circuit Check
- Brake Signal Circuit Check (All Engines)
- Torque Converter Clutch (TCC) Circuit Check
- Shift Solenoid "A" Circuit Check
- Shift Solenoid "B" Circuit Check
- Force Motor Circuit Check