P0351 on Pontiac: How to Diagnose & Fix
Ignition Coil A Primary/Secondary Circuit Malfunction
1 Pontiac model · 1 documented issue · 1 critical · $400-$1,000 repair
P0351 on Pontiac by model: symptoms, diagnosis and fix
1993-1997 Firebird/Trans Am with the LT1 5.7L V8 (same engine in Camaro Z28, Corvette C4, and some Buick Roadmaster/Caprice/Impala SS) suffers infamous Optispark distributor failure. The distributor sits at the front of the engine behind the water pump — coolant leaks from the water pump (or condensation from the front of the engine) drip directly into the Optispark and short the optical sensors. Symptoms: misfire, no-start, rough running in wet weather.
Common Symptoms
- misfire
- no-start when wet
- rough idle
- random cylinder misfire codes
How to Fix
Replace Optispark with a 1995+ vented Delco unit ($250-$500 part). ALWAYS replace the water pump at the same time ($150-$250 part) — they are the same labor job (water pump must come off to access the Optispark). Total job ~$400-$900 at independent. Confirm the vent tube routing on later "vented" Optispark.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- AIP D92LT new non-vented Optispark distributor
Do not use as a 1995-1997 vented unit.
- AIP D95LT new vented second-generation Optispark distributor
Confirm vent and vacuum-harness routing.
- ENC-1182 LT1 cam-driven aluminum water pump with gaskets
Confirm drive/seal condition and current installation procedure.
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P0351 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0351 mean on a Pontiac?
P0351 stands for "Ignition Coil A Primary/Secondary Circuit Malfunction." P0351 indicates the engine computer found a fault in the primary or secondary circuit of ignition coil 'A' (typically the coil for cylinder 1 or the first coil in the firing system). The PCM monitors the coil's control circuit, and when the electrical feedback doesn't match what it expects during firing, it sets this code. Because the coil creates the high-voltage spark, this often causes a misfire, rough idle, hesitation, or loss of power. It is a circuit/component fault for one specific coil rather than a general engine problem. On Pontiac it is documented across 1 model: Firebird.
What are the most common causes of P0351?
The most common causes of P0351 are: Failed or weak ignition coil, Damaged or corroded coil connector or pigtail, Broken or shorted wiring in the coil control circuit, Loss of power feed or ground to the coil, Worn or fouled spark plug overloading the coil, Failed coil driver inside the PCM/ECM. The specific cause varies by vehicle.
How much does it cost to fix P0351 on a Pontiac?
Published repair estimates on Pontiac range from $400 to $1,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0351 on a different make?
View P0351 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.