Engine

P0287 — Cylinder 9 Contribution/Balance Fault

Severity: medium Drive with care, to a shop

What P0287 means

P0287 means the engine control module detected that cylinder 9 is not contributing its share of power. The module monitors crankshaft speed changes and compares each cylinder against the others. When cylinder 9 lags, the code is set. It only applies to engines with nine or more cylinders, typically V10 and V12 designs.

Symptoms

  • Check Engine light is on
  • Rough idle and engine vibration
  • Reduced power and sluggish acceleration
  • Higher fuel consumption
  • Misfire felt on one cylinder

Possible causes

  1. Clogged or failing fuel injector on cylinder 9
  2. Damaged wiring or connector in the injector circuit (open, corrosion, short to ground)
  3. Low compression or a mechanical fault in cylinder 9 (valve, rings, head gasket)
  4. Failed ignition coil or spark plug on cylinder 9
  5. Vacuum leak near that cylinder
  6. Rarely, an ECM fault or outdated calibration

How to diagnose

  1. Scan all codes and freeze frame data, and look for related misfire codes such as P0309
  2. Confirm which physical cylinder is number 9 using the manufacturer's layout
  3. Inspect the injector and coil connectors and wiring for cylinder 9 for damage or corrosion
  4. Check the spark plug and coil, or swap them with another cylinder to see if the fault follows
  5. Test injector resistance and operation with a stethoscope or scope
  6. Check fuel pressure and look for vacuum leaks
  7. Run a compression or leak-down test on cylinder 9
  8. If all passes, check for ECM software updates and the module itself

Common fixes

  • Clean or replace the cylinder 9 fuel injector
  • Repair or replace damaged wiring and connectors
  • Replace the spark plug or ignition coil on the affected cylinder
  • Repair the mechanical fault in the cylinder (valves, rings, cylinder head)
  • Reflash or replace the ECM if confirmed faulty

Questions and answers

What does P0287 mean?

It is a cylinder 9 contribution/balance fault: the engine computer sees that cylinder producing less power than the others. The usual suspects are the injector, wiring or an engine mechanical problem.

Can I drive with P0287?

A short, easy drive to a shop is usually okay. If the check engine light flashes, the engine shakes badly or power drops sharply, stop to avoid damaging the catalytic converter.

How do I tell an injector problem from a mechanical one?

Swap the coil, plug or injector with a neighboring cylinder. If the fault moves, that part is bad. If it stays on cylinder 9, do a compression test.

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.