P0263: cylinder 1 isn't contributing its share of power
The engine control unit can work out roughly how much each cylinder is contributing to the engine's power by watching how evenly the crankshaft speeds up on each cylinder's power stroke. This code means cylinder 1 is contributing less than the computer expects, measured by a different check from the one that sets a misfire code. It doesn't say why that cylinder is under-contributing, only that it is.
You might notice
- The engine warning light comes on
- The engine may feel slightly rough or down on power
- contribution/balance
- — roughly how much power each cylinder is adding, judged from how the crankshaft speeds up on its power stroke
- crankshaft
- — the rotating shaft the pistons turn, which drives the car
What this code means for driving
Short local trips only
The engine's own measurement says a cylinder is not contributing its share of power: it compares how much the crankshaft speeds up on each power stroke. Unburnt fuel from a cylinder that is down on power can damage the catalytic converter, so this is a garage job rather than something to carry on driving with.
Pull over as soon as it's safe if a red warning light comes on or the car starts to drive differently. If your car has an engine, also pull over if the engine light starts flashing or the engine shakes badly or loses power.
The car will still drive, but a cylinder that is down on power can put unburnt fuel through the catalytic converter, so keep trips short and get it looked at.
This is what P0263 means taken alone, and that part won't change no matter what else your scan turns up. What's actually causing it can still depend on the rest of your codes. Read it with your other codes.
What the code itself says
P0263 is a powertrain (engine, gearbox and drive system) code, and the 0 after the letter means it is a generic code with a standard meaning.
Grouped here as: Engine running, fuelling and misfires — Air metering, fuelling, ignition, misfire, idle, boost, knock, oxygen sensors and the catalyst, all working together in the running engine. That grouping is ours, to help explain the code. The code's official family is the letter at the start.
This page is generic. Your car isn't.
A code on its own only tells you what the sensor saw, not what's actually wrong — and that changes next to your other codes. Read this one together with the rest of your scan and we'll work out what's really going on.
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