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 MANUALSPONTIAC1991FIREBIRD FORMULA, 5.0 F, STANDARD, M39REPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 15 (ENGINE CONTROLS - TESTS W/CODES - 3.1L PFI)PCM/BCM CODE CHARTSCODE 41, CYLINDER SELECT ERRORDIAGNOSTIC AIDS

1991 Pontiac Firebird Formula, 5.0 F, Standard, M39

Diagnostic Aids

1991 Pontiac Firebird Formula, 5.0 F, Standard, M39SECTION Diagnostic Aids

WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 1992 Pontiac Sunbird, 1992 Pontiac Grand Prix, 1992 Pontiac Firebird, 1992 Oldsmobile Cutlass Supreme, and 1992 Chevrolet Lumina. However, it is still accessible from the selected car via links, so may be relevant.

Check MEM-CAL to be sure locking tabs are secure. Also check pins on both MEM-CAL and ECM to verify proper contact. Check MEM-CAL part number for proper application. If correct MEM-CAL is installed and is defective, ECM may also need replacing.

Fig 1: Code 41, Flow Chart, Cylinder Select Error

RENDER: 1.0x

NO RELATED

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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.