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.
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HOMESERVICE MANUALSPONTIAC1987FIREBIRD FORMULA, 5.0 H, AUTOMATICREPAIR AND DIAGNOSISENGINE PERFORMANCESYSTEM5.0L/5.7L PFI TESTS W/CODES
1987 Pontiac Firebird Formula, 5.0 H, Automatic
5.0L/5.7L PFI Tests W/Codes
1987 Pontiac Firebird Formula, 5.0 H, AutomaticSECTION 5.0L/5.7L PFI Tests W/Codes
- Description
- Diagnosis & Testing
- Diagnostic Charts
- Diagnostic Circuit Check
- Chart A1 - No "Service Engine Soon" ("SES") Light
- Chart A2 - No ALDL/Won't Flash Code 12 "SES" Light On Steady
- Chart A3 - Cranks/Won't Run
- Chart A7 - Fuel System Diagnosis
- Chart A9 - Cold Start Valve
- Chart B1 - Restricted Exhaust System Check
- Code 13 - Open Oxygen Sensor Circuit
- Code 14 - Coolant Temperature Sensor (Cts) Signal Voltage Low
- Code 15 - Cts Signal Voltage High
- Code 21 - TPS Signal Voltage High
- Code 22 - Throttle Position Sensor Signal Voltage Low
- Code 23 - Mat Sensor Signal Voltage High
- Code 24 - Vehicle Speed Sensor
- Code 25 - Manifold Air Temperature Sensor Signal Voltage Low
- Code 32 - EGR System Failure
- Code 33 - MAF Sensor Voltage High
- Code 34 - MAF Sensor Voltage Low
- Code 36 - MAF Burn-Off Failure
- Code 41 - CYL Select Error
- Code 42 - Est (W/HEI)
- Code 43 - Electronic Spark Control
- Code 44 - Lean Exhaust Indication
- Code 45 - Rich Exhaust Indication
- Code 51 - Faulty Mem-Cal
- Code 53 - System Over Voltage
- Code 54 - Fuel Pump Voltage Low
- Code 55 - ECM Error
- Chart C1A - Park/Neutral Switch
- Chart C2A - Injector Balance Test
- Chart C2C - Idle Air Control
- Chart C3 - Canister Purge Check
- Chart C4 - Ignition System Check (W/HEI)
- Chart C5 - Electronic Spark Control
- Chart C6B - Air Management Check
- Chart C7 - EGR Check
- Chart C8A - TCC, (1 Of 2)
- Chart C8A - TCC, (2 Of 2)
- Chart C8B - Shift Indicator
- Chart C12 - Cooling Fan CKT, (1 Of 2)
- Chart C12 - Cooling Fan CKT, (2 Of 2)
- Component Locations
- ECM Terminal Identification
- Wiring Diagrams
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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.