Faulty spark plug or ignition coil on cylinder 5; Clogged or malfunctioning fuel injector for cylinder 5; Vacuum leak affecting cylinder 5 intake path; Low compression due to worn piston rings, valves, or head gasket; Wiring or connector issue to the cylinder 5 injector or ignition coil; Mechanical valvetrain fault such as a worn cam lobe or collapsed lifter

DTC codes / P02xx · Fuel and air metering (injector circuits) / P0275

P0275Cylinder 5 Contribution/Balance

Q: What does code P0275 mean?

Cylinder 5 Contribution/Balance. P0275 is a generic powertrain code that indicates the engine control module has detected an abnormal contribution from cylinder 5 to overall engine power, typically by monitoring crankshaft speed fluctuations. The computer compares the acceleration of the crankshaft during each cylinder's power stroke and flags cylinder 5 when its contribution deviates beyond a calibrated threshold.

P0275 is a generic powertrain code that indicates the engine control module has detected an abnormal contribution from cylinder 5 to overall engine power, typically by monitoring crankshaft speed fluctuations. The computer compares the acceleration of the crankshaft during each cylinder's power stroke and flags cylinder 5 when its contribution deviates beyond a calibrated threshold.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
A noticeable engine misfire or rough running condition, especially under load or at idle
Shaking or vibration felt through the steering wheel or seat
Reduced engine power and poor acceleration
A flashing check engine light in severe cases, indicating a misfire that could damage the catalytic converter
Poor fuel economy or an increase in exhaust emissions

Common causes, most likely first

Faulty spark plug or ignition coil on cylinder 5
Clogged or malfunctioning fuel injector for cylinder 5
Vacuum leak affecting cylinder 5 intake path
Low compression due to worn piston rings, valves, or head gasket
Wiring or connector issue to the cylinder 5 injector or ignition coil
Mechanical valvetrain fault such as a worn cam lobe or collapsed lifter

How to diagnose and fix it

Perform a visual inspection of the cylinder 5 ignition coil, spark plug, and injector connectors for damage or corrosion
Swap the ignition coil and spark plug from cylinder 5 with a known-good cylinder to see if the misfire moves
Use a scan tool to check for pending or stored misfire codes on other cylinders and review freeze-frame data
Run a compression test and a cylinder leak-down test on cylinder 5 to rule out mechanical faults
Test the fuel injector for cylinder 5 with a noid light or injector balance test
Check for vacuum leaks using a smoke machine or propane enrichment test
If the misfire persists after swapping components, perform a crankshaft position variation relearn or inspect the reluctor wheel

What a cylinder contribution code really means

A P0275 does not always mean the ignition system is at fault; a dirty or failing fuel injector is a common culprit that many technicians overlook.
The code can be set by a mechanical issue such as a worn camshaft lobe or a sticking valve that does not show up in a simple compression test.
A vacuum leak at the intake manifold gasket near cylinder 5 can cause a lean misfire that mimics a bad injector.
Some vehicles require a crankshaft position variation relearn after replacing the engine or flywheel, and failing to do so can set a false P0275.
A flashing check engine light with P0275 indicates a misfire severe enough to damage the catalytic converter, so driving should be limited until repaired.

Can I keep driving with P0275?

It is generally safe to drive with a steady check engine light, but avoid heavy acceleration and prolonged driving until the misfire is diagnosed. If the check engine light is flashing, stop driving as soon as possible to prevent catalytic converter damage.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.