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.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSPONTIAC1991FIREBIRD FORMULA, 5.0 F, STANDARD, M39REPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 17 (ENGINE CONTROLS - TESTS W/CODES - 5.0L TBI)
1991 Pontiac Firebird Formula, 5.0 F, Standard, M39
Section 17 (Engine Controls - Tests W/Codes - 5.0L TBI)
1991 Pontiac Firebird Formula, 5.0 F, Standard, M39SECTION Section 17 (Engine Controls - Tests W/Codes - 5.0L TBI)
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 1992 Pontiac Firebird, 1992 Oldsmobile Custom Cruiser, 1992 Chevrolet Caprice, 1992 Chevrolet Camaro, and 1992 Cadillac Brougham. However, it is still accessible from the selected car via links, so may be relevant.
- Introduction
- Model Identification
- Self-Diagnostic System
- Pcm/BCM Code Charts
- Notes
- Code 13, Open Oxygen (O2) Sens CKT
- Code 14, Coolant Temp Sens, Signal Voltage Low
- Code 15, Coolant Temp Sens, Signal Voltage High
- Code 21, Throttle Position Sens, Signal Voltage High
- Code 22, Throttle Position Sens, Signal Voltage Low
- Code 23, Mat Sens Signal Voltage High
- Code 24, Vehicle Speed Sens (VSS)
- Code 25, Mat Sens Signal Voltage Low
- Code 32, EGR System Error (1 Of 3)
- Code 32, EGR System Error - Positive BACKPRESSURE (2 Of 3)
- Code 32, EGR System Error - Negative BACKPRESSURE (3 Of 3)
- Code 33, Map Sens, Signal Voltage High
- Code 34, Map Sens, Signal Voltage Low
- Code 35, IAC Idle Speed Error, W/O Tech 1
- Code 35, IAC Idle Speed Error, Using Tech I
- Code 42, Est CKT Open Or Grounded
- Code 43, ESC Error, W/ESC Module
- Code 43, ESC Error, W/O ESC Module
- Code 44, Lean Exhaust Indication
- Code 45, Rich Exhaust Indication
- Code 51, Faulty Prom/Mem-Cal
- Code 52, Faulty Cal-PAK
- Code 53, Vehicle Anti-Theft SYS, "F" Body
- Code 54, Fuel Pump Voltage Low
- Code 55, ECM Error
- Summary
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.