P0263 on Chevrolet: How to Diagnose & Fix
Cylinder 1 Contribution/Balance
1 Chevrolet model · 1 documented issue · 1 critical · $1,500-$4,000 repair
P0263 on Chevrolet by model: symptoms, diagnosis and fix
Bosch fuel injectors on early Duramax engines develop internal leaks causing rough running, white smoke, and hard starts. LB7 generation (2001-2004) most affected; GM extended injector coverage to 7 years/200,000 miles under a special policy that has since expired.
Common Symptoms
- Rough idle
- White smoke from exhaust
- Hard cold starting
- Fuel knock or miss
- Reduced fuel economy
- Fuel in oil
How to Fix
Replace failed injectors. Consider replacing all 8 as preventive measure. Use updated Bosch injector part numbers. Replace injector return lines and cups at same time.
Sources for this issue (3)
P0263 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 P0263 mean on a Chevrolet?
P0263 stands for "Cylinder 1 Contribution/Balance." This code means the engine computer has detected a contribution or balance problem on cylinder 1, indicating that this cylinder is producing more or less power than the others. The computer monitors tiny speed changes from each cylinder's firing event and flags one that is contributing unevenly. It points to a fueling, compression, or mechanical imbalance specific to cylinder 1 (and, on some diesels, a related fuel injector circuit). You may notice rough idle, a misfire feel, or reduced power. On Chevrolet it is documented across 1 model: Silverado 2500HD.
What are the most common causes of P0263?
The most common causes of P0263 are: Faulty fuel injector on cylinder 1, Clogged or leaking cylinder 1 injector, Low compression in cylinder 1 (valves, rings, head gasket), Worn or fouled spark plug / coil on cylinder 1 (gas engines), Injector wiring or connector fault on cylinder 1, Vacuum or intake leak affecting that cylinder, Carbon buildup or sticking valve on cylinder 1. The specific cause varies by vehicle.
How much does it cost to fix P0263 on a Chevrolet?
Published repair estimates on Chevrolet range from $1,500 to $4,000 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.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.