What it means
The control module detected that cylinder 10 is not contributing to engine power as expected. Possible causes include an injector, compression, or other cylinder-specific problem.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The control module estimates each cylinder's contribution to engine output by monitoring how evenly the engine runs. P0290 means cylinder 10 is contributing less than expected, which can result from a cylinder-specific fuel, ignition, compression, or wiring problem.
Common causes
Most likely first.
- Cylinder 10 injector restricted or faulty
- Cylinder 10 ignition coil or spark plug fault
- Low compression on cylinder 10
- Wiring or connector fault
Symptoms
- Check-engine light
- Rough idle or engine vibration
- Reduced power
- Engine misfire
How to diagnose it
- Use a scan tool to check freeze-frame data, misfire counts, and cylinder contribution readings to confirm the fault is concentrated on cylinder 10.
- Inspect cylinder 10's injector and wiring connector, and check its spark plug and ignition coil if the engine uses spark ignition.
- Test the cylinder 10 injector's electrical operation and compare its response with other cylinders using the manufacturer's procedure.
- If the fuel and ignition checks pass, perform a compression test on cylinder 10 and compare it with the manufacturer's specification.
- If compression is low, perform a leak-down test to help locate the source of the cylinder 10 sealing problem.
Common fixes
- Repair a loose or damaged cylinder 10 connector or wiring.
- Replace a faulty cylinder 10 spark plug or ignition coil, if fitted.
- Clean or replace a restricted or faulty cylinder 10 injector.
- Repair the mechanical fault identified by compression or leak-down testing.
Can I keep driving?
A weak cylinder 10 can make the engine run roughly and lose power; continued misfiring can damage the exhaust catalyst. Avoid hard acceleration and stop driving if the engine runs severely rough or the warning light flashes.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.