Engine

P0281 — Cylinder 7 Contribution/Balance Fault

Severity: medium Drive with care, to a shop

What P0281 means

The engine control module compares how much each cylinder contributes to crankshaft speed, often by watching tiny changes in rotation. P0281 means cylinder 7 is producing noticeably less power than calibrated limits allow. The cause can be fuel delivery, spark, compression or the electrical circuit for that cylinder.

Symptoms

  • Check engine light on
  • Rough idle
  • Loss of power
  • Sluggish acceleration
  • Poor fuel economy
  • Engine vibration

Possible causes

  1. Faulty or clogged cylinder 7 fuel injector
  2. Cylinder 7 ignition fault: coil, spark plug or wiring
  3. Low compression in cylinder 7 (valve, rings or piston)
  4. Open, corroded or loose wiring or connector at the injector or coil
  5. Vacuum leak or fuel supply problem affecting that cylinder
  6. Rarely, an ECM fault or software issue

How to diagnose

  1. Read all codes and freeze frame data; look for misfire codes such as P0307
  2. Inspect the injector and coil connectors and wiring for cylinder 7
  3. Swap the cylinder 7 coil (and plug) with another cylinder and see if the fault follows
  4. Inspect the spark plug for wear, oil, deposits and gap
  5. Test the injector: resistance, control signal, clicking sound, flow test if needed
  6. Run a compression or cylinder leakdown test
  7. Review scan tool cylinder balance and fuel trim data
  8. Check for ECM software updates for your vehicle

Common fixes

  • Clean or replace the cylinder 7 fuel injector
  • Replace the spark plug, ignition coil or damaged wiring
  • Repair the harness and connectors and clean the contacts
  • Repair the engine internally if compression is low (valves, rings, piston)
  • Update or replace the ECM only after everything else is ruled out

Questions and answers

What does P0281 mean?

The engine computer found that cylinder 7 is working weaker than the others. The usual culprits are the injector, ignition, compression or wiring for that cylinder.

Can I drive with code P0281?

Only for a short distance and under light load. Running with a weak cylinder can damage the catalytic converter, so don't put off diagnosis.

How do I find the cause of P0281 quickly?

Swap the coil and spark plug with a neighboring cylinder. If the code moves, it's ignition. If not, check the injector and compression.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.