What it means
The control module detected that cylinder 5 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 compares how much each cylinder contributes to engine speed and power during combustion. P0275 identifies cylinder 5 as contributing less than expected, but the cause may be its injector, ignition components, wiring, compression, or another cylinder-specific problem.
Common causes
Most likely first.
- Cylinder 5 injector restricted or faulty
- Cylinder 5 ignition coil or spark plug fault
- Low compression on cylinder 5
- Wiring or connector fault
Symptoms
- Check-engine light
- Rough idle or engine vibration
- Reduced power
- Engine misfire
How to diagnose it
- Save freeze-frame data and review cylinder-specific misfire or balance data to confirm cylinder 5 is the weak contributor.
- Inspect cylinder 5's injector, ignition coil, spark plug, connectors, and nearby wiring for visible damage or poor connections.
- Check the cylinder 5 spark plug and ignition operation, comparing with other cylinders where the vehicle's procedure permits.
- Test cylinder 5 injector electrical operation and fuel delivery against the manufacturer's procedure.
- Measure cylinder 5 compression and compare it with the other cylinders and the manufacturer's specification.
Common fixes
- Repair a loose or damaged cylinder 5 ignition or injector connection.
- Replace a confirmed faulty cylinder 5 spark plug or ignition coil.
- Clean or replace a restricted or faulty cylinder 5 injector after testing confirms it.
- Repair the cylinder 5 mechanical fault identified by compression testing.
Can I keep driving?
Avoid hard acceleration and prolonged driving while the engine misfires, because the catalytic converter can be damaged. Stop if the engine shakes heavily, loses significant power, or the misfire worsens.
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.