Repair manual
GMC S15 Pickup Repair Manual
Step-by-step repair and maintenance instructions for the GMC S15 Pickup (1985–1988): removal, installation, adjustment, diagnostics and parameter checks with illustrations.
- BASIC DIAGNOSTIC PROCEDURE - TESTING
- CLEARING TROUBLE CODES
- READING TROUBLE CODES
- TROUBLE CODE IDENTIFICATION - TBI MODELS
- TROUBLE CODE DETERMINATION (HARD OR INTERMITTENT)
- DIAGNOSTIC CHARTS
- DIAGNOSTIC CIRCUIT CHECK
- DIAGNOSTIC SYMPTOM CHECK
- FIELD SERVICE MODE
- DIAGNOSTIC TOOLS
- "NON-SCAN" DIAGNOSTIC CIRCUIT CHECK
- "SCAN" DIAGNOSTIC CIRCUIT CHECK - TESTING
- CHART A1 - NO "SERVICE ENGINE SOON" LIGHT
- CHART A2 - NO CODE 12, "SERV ENG SOON" LIGHT ON STEADY
- CHART A3 - ENGINE CRANKS, BUT WILL NOT RUN (1 OF 2)
- CHART A4 - ENGINE CRANKS, BUT WILL NOT RUN (2 OF 2)
- CHART A5 - FUEL SYSTEM DIAGNOSIS (1 OF 3)
- CHART A6 - FUEL SYSTEM DIAGNOSIS (2 OF 3)
- CHART A7 - FUEL SYSTEM DIAGNOSIS (3 OF 3)
- CODE 13 - OXYGEN (O2) SENSOR CIRCUIT
- CODE 14 - COOLANT SENSOR CIRCUIT (SIGNAL VOLTAGE LOW)
- CODE 15 - COOLANT SENSOR CIRCUIT (SIGNAL VOLTAGE HIGH)
- CODE 21 - THROTTLE POSITION SENS (TPS) (SIGNAL VOLTAGE HIGH)
- CODE 22 - THROTTLE POSITION SENSOR (TPS) (SIGNAL VOLTAGE LOW)
- CODE 24 - VEHICLE SPEED SENSOR (VSS)
- CODE 33 - MAP SENSOR (SIGNAL VOLTAGE HIGH)
- CODE 34 - MAP SENSOR (SIGNAL VOLTAGE LOW)
- CODE 35, IDLE AIR CONTROL (IAC)
- CODE 42 - ELECTRONIC SPARK TIMING (EST)
- CODE 44 - LEAN EXHAUST INDICATION
- CODE 45 - RICH EXHAUST INDICATION
- CODE 51 - FAULTY PROM
- CODE 55 - FAULTY ECM
- CHART C1 - ECM REPLACEMENT CHECK CHART