Fuel and air

P0283 — Cylinder 8 Injector Circuit High

Severity: medium Drive with care, to a shop

What P0283 means

The engine control unit fires the cylinder 8 injector by switching its circuit to ground in short pulses. P0283 sets when the voltage in that circuit is higher than expected, for example from a short to power, an open circuit or a failing driver in the PCM. The injector may then fire incorrectly or not at all.

Symptoms

  • Check Engine light on
  • Rough or uneven idle
  • Loss of power and hesitation under load
  • Higher fuel consumption
  • Misfire on cylinder 8
  • Engine stumbling during acceleration

Possible causes

  1. Failed cylinder 8 fuel injector (open or shorted coil)
  2. Damaged or corroded injector wiring or connector
  3. Injector control wire shorted to power
  4. Poor ground or bad connection in the injector circuit
  5. Failed injector driver inside the PCM
  6. Blown fuse or faulty relay feeding the injectors

How to diagnose

  1. Scan for codes and freeze-frame data, and note any other injector or misfire codes.
  2. Inspect the cylinder 8 injector connector and harness for chafing, corrosion or heat damage.
  3. Check the fuse and relay that power the injectors.
  4. Measure injector coil resistance and compare it with the spec for your engine.
  5. Check for supply voltage at the connector with the key on, and for control pulses with a noid light or scope.
  6. Test the control wire from the PCM to the injector for opens and shorts to power.
  7. Swap the injector with a neighboring cylinder: if the code follows, the injector is bad.
  8. If wiring and injector test fine, suspect the PCM driver.

Common fixes

  • Replace the cylinder 8 fuel injector
  • Repair or replace the damaged wiring or connector
  • Replace the blown fuse or faulty relay
  • Repair or replace the PCM if its driver has failed

Questions and answers

What does P0283 mean?

The PCM sees too high a voltage in the cylinder 8 injector control circuit. The cause is usually the wiring, the injector itself or the PCM driver.

Can I drive with a P0283 code?

Only briefly and gently, such as to a shop. Misfires can damage the catalytic converter, and extra fuel can wash oil off the cylinder wall.

How do I tell if it's the injector or the PCM?

Check the injector resistance and wiring first, then swap the injector with a neighboring cylinder. If the code moves, the injector is bad. If it stays on cylinder 8, look at the harness or the PCM.

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.