Repair manual
GMC S15 Pickup Repair Manual
Step-by-step repair and maintenance instructions for the GMC S15 Pickup (1987–1991): removal, installation, adjustment, diagnostics and parameter checks with illustrations.
- MODEL IDENTIFICATION
- BASIC DIAGNOSTIC PROCEDURES
- CLEARING TROUBLE CODES
- Without "SCAN" Tester
- With "SCAN" Tester
- TROUBLE CODE DETERMINATION (HARD OR INTERMITTENT)
- Diagnostic Charts
- System Check
- Field Service Mode Check
- DIAGNOSTIC TOOLS
- Circuit Description
- Test Description
- Diagnostic Aids
- Fuel Module Check Procedure
- System Too Lean (High Air/Fuel Ratio)
- System Too Rich (Low Air/Fuel Ratio)
- Throttle Body
- A/C Compressor Relay Failure
- O2 Sensor Wire
- Fuel Contamination
- Fuel Pressure
- AIR System
- Circuit No. 413
- Sensor Harness
- HEI Shielding
- Canister Purge
- MAP Sensor
- Pressure Regulator
- TPS
- CODE 51 - FAULTY MEM-CAL (2.5L)
- CODE 51 - PROM PROBLEM (2.8L/4.3L/5.0L/5.7L/7.4L)
- CODE 52 - FUEL CALPAK MISSING (2.8L/4.3L/5.0L/5.7L/7.4L)
- CODE 53 - SYSTEM OVER VOLTAGE (2.5L)
- CODE 55 - ECM PROBLEM (2.8L/4.3L/5.0L/7.4L)
- Circuit Test Description
- A/C Compressor Or Relay Failure