Repair manual
Chevrolet Step Van P20 Repair Manual
Step-by-step repair and maintenance instructions for the Chevrolet Step Van P20 (1985–1986): removal, installation, adjustment, diagnostics and parameter checks with illustrations.
- DIAGNOSTIC CIRCUIT CHECK - TESTING
- SYSTEM PERFORMANCE CHECK
- CHART A1 - DWELL FIXED UNDER 10°
- CHART A2 - DWELL FIXED BETWEEN 10°-50°
- CHART A3 - DWELL FIXED OVER 50°
- CHART A5 - "CHECK ENGINE" LIGHT INOPERATIVE
- WON'T FLASH CODE 12 OR "CHECK ENGINE" LIGHT ON AT ALL TIMES
- CODE 12 - NO DISTRIBUTOR REFERENCE PULSES
- CODE 13 - OXYGEN SENSOR CIRCUIT
- CODE 14 - COOLANT SENSOR SHORTED
- CODE 15 - COOLANT SENSOR OPEN
- CODE 21 - TPS CIRCUIT HIGH
- CODE 23 - M/C SOLENOID CIRCUIT LOW
- CODE 34 - DIFFERENTIAL PRESSURE (VACUUM) SENSOR
- CODE 41 - NO DISTRIBUTOR REFERENCE SIGNAL
- CODE 42 - ELECTRONIC SPARK TIMING (EST)
- CODE 43 - ELECTRONIC SPARK CONTROL (4.3L ONLY)
- CODE 44 - LEAN EXHAUST INDICATION
- CODE 45 - RICH EXHAUST INDICATION
- CODE 51 - FAULTY PROM
- CODE 54 - M/C SOLENOID CIRCUIT VOLTAGE HIGH
- CHART C1 - ECM REPLACEMENT CHECK CHART