Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1986 Chevrolet Cavalier RS, 2D Hatchback, 2.8 W, AutomaticFACTORY OEM SERVICE PROCEDURE
2.0L TBI Tests W/Codes
- Model Identification
- Description
- Diagnostic System Operation
- Basic Diagnostic Procedure
- Entering Or Exiting Diagnostic Mode (Non-Scan)
- Reading Trouble Codes
- ECM Trouble Code Definitions
- Trouble Code Determination (Hard Or Intermittent)
- Clearing Trouble Codes
- Diagnostic Materials
- Special Diagnostic Tools
- Scan Tester Usage
- Scan Tester - Test Data Parameters
- "Non-Scan" Diagnostic Circuit Check
- "Scan" Diagnostic Circuit Check
- Chart A1 - No "Service Engine Soon" Light
- Chart A2 - Won't Flash Code 12 "SES" Always On
- Charts A3 & A4 - Engine Cranks, But Won't Run
- Charts A5 & A6 - Fuel System Diagnosis
- Code 13 - Open Oxygen Sensor Circuit
- Code 14 - Coolant Sensor Signal Voltage Low
- Code 15 - Coolant Sensor Signal Voltage High
- Code 21 - TPS Signal Voltage High
- Code 22 - 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 42 - Electronic Spark Timing (Est)
- Code 44 - Lean Exhaust Indication
- Code 45 - Rich Exhaust Indication
- Code 51 - Prom Failure
- Code 52 - Fuel Calpac Missing
- Code 54 - Fuel Pump Circuit, Low Voltage
- Code 55 - Replace ECM
- Chart C1 - ECM Replacement Check Chart
- Chart C1A - Park/Neutral Switch (Auto Trans.)
- Chart C1B - Crank Signal
- Chart C1D - Map Output Check
- Chart C1E - Power Steering Pressure Switch (PSPS)
- Chart C2C - Idle Air Control (IAC)
- Chart C4B - Ignition System Check
- Chart C7A - EGR Valve Check
- Chart C8 - 125C Torque Converter Clutch (TCC)
- Chart C8B - Manual Transaxle Shift Light
- Chart C10B - A/C Clutch Control
- Chart C12B - Engine Cooling Fan
- Component Locations
- ECM Terminal Identification & Pin Voltages
- Wiring Diagram
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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