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 MANUALSPONTIAC1987FIREBIRD FORMULA, 5.0 H, AUTOMATICREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCETESTING & DIAGNOSIS5.0L/5.7L PFI TESTS W/CODESDIAGNOSTIC CHARTSCODE 43 - ELECTRONIC SPARK CONTROLDIAGNOSTIC AIDS

1987 Pontiac Firebird Formula, 5.0 H, Automatic

Diagnostic Aids

1987 Pontiac Firebird Formula, 5.0 H, AutomaticSECTION Diagnostic Aids

Code 43 can be caused by a faulty connection at the knock sensor, ESC module or at the ECM. Also, check circuit No. 485 for possible open or short to ground.

Fig 1: Code 43 Flow Chart - ESC

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.

Shop Manual-Ready Tools Free Quote Check Quote Shield Pro

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.