4.3L/5.0L/5.7L Tests W/Codes

• 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
• Chart A6 - No Code 12/"Check Engine" Light Always On
  • 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
• Chart C1E - Vac Sensor
• Chart C2F - TPS Enrichment Check
• Chart C2T - Throttle Kicker (4.3L W/ A/C Only)
• Chart C2T - Throttle Kicker (4.3L W/O A/C Only)
• Chart C3 - Canister Purge Valve Check
• Chart C4A - IGN System (All W/ Integral Coil)
• Chart C4D - Est Performance Check
• Chart C5 - ESC Check (No Code 43)
  • Electronic Spark Control (ESC) Check - Engine Knock, Poor Performance Or Poor Economy (No Code 43)
• Chart C6C - Electric Diverter Valve (EDV) Check
• Chart C7A - EGR Valve (PWM)
  • EGR Valve Check/Pulse Width Modulated (PWM) EGR
• Chart C7C - EGR Valve Check (Non-ECM Controlled)
• Chart C8B - TCC Electrical Diagnosis (All Exc. 4.3L)
• CHART C8C - TCC Electrical Diagnosis (4.3L ONLY)
• Chart C9C - EFE Check
• Park Neutral Switch Diagnosis (Auto Trans Only)
• Crank Signal
• Map Output Check
• Power Steering Pressure Signal
• EGR Valve Check Non-ECM Controlled
• Transmission Converter Clutch (TCC) Elect. Diagnosis
• Shift Light
• A/C Clutch Control
• Wiring Diagram