Engine

P0290 — Cylinder 10 Contribution/Balance Fault

Severity: medium Drive with care, to a shop

What P0290 means

The engine control module constantly compares how much each cylinder contributes to engine output, for example by watching crankshaft speed variations. P0290 sets when cylinder 10 is noticeably weaker than the others and falls outside the expected limits. The cause can be fuel delivery, ignition, wiring or a mechanical problem. This code applies to engines with ten or more cylinders, such as V10 and V12 engines.

Symptoms

  • Check Engine light on
  • Rough idle
  • Hesitation or shaking under acceleration
  • Reduced power
  • Worse fuel economy
  • Fuel smell from the exhaust

Possible causes

  1. Faulty or clogged fuel injector on cylinder 10
  2. Open, short or corroded connector in the cylinder 10 injector circuit
  3. Worn spark plug or failing ignition coil on cylinder 10
  4. Low compression from worn rings, valves or a burned piston or valve
  5. Fuel system problems such as low pressure or a vacuum leak
  6. Rarely, a faulty ECM

How to diagnose

  1. Read all codes and freeze frame data, and look for related misfire or fuel trim codes
  2. Use the firing order diagram to find which physical cylinder is labeled cylinder 10 on this engine
  3. Inspect the wiring and connectors at the cylinder 10 injector and coil for damage and corrosion
  4. Swap the coil (or plug) with one from a healthy cylinder and see whether the fault follows
  5. Inspect the spark plug for wear, gap, and oil or fuel fouling
  6. Test injector resistance and operation, listen for clicking with a stethoscope, and run a flow test if needed
  7. Measure fuel rail pressure
  8. Run a compression or cylinder leakdown test

Common fixes

  • Replace the spark plug or ignition coil on cylinder 10
  • Clean or replace the cylinder 10 fuel injector
  • Repair damaged injector or coil wiring and connectors
  • Correct fuel system problems (pressure, air leaks)
  • Repair internal engine damage (rings, valves, cylinder head)

Questions and answers

What does P0290 mean?

It means the ECM judges cylinder 10 to be underperforming compared with the other cylinders. The usual culprits are the injector, spark plug, ignition coil or wiring.

Can I drive with P0290?

Only for a short distance and under light load to get to a shop. Extended driving with a misfire can damage the catalytic converter. If the Check Engine light flashes, do not drive.

How can I quickly narrow down the cause of P0290?

Swap the cylinder 10 coil or spark plug with a neighboring cylinder and clear the code. If the fault moves, the ignition part is bad. If it stays, check the injector, wiring 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.