Fuel and air

P02D5 — Cylinder 5 Injector Offset Learning at Max Limit

Severity: medium Drive with care, to a shop

What P02D5 means

The engine control module learns a small correction for each fuel injector so every cylinder gets an equal amount of fuel. P02D5 means the correction for cylinder 5 has hit its maximum, so the ECM can't compensate any further. The cause is usually the injector itself, its wiring, fuel pressure, or the mechanical condition of that cylinder.

Symptoms

  • Check engine light on
  • Rough idle
  • Hesitation or stumbling under acceleration
  • Reduced engine power
  • Worse fuel economy
  • Possible cylinder 5 misfire

Possible causes

  1. Clogged or worn cylinder 5 fuel injector
  2. Damaged wiring or a poor connection at the injector connector
  3. Low fuel pressure from a weak pump or clogged filter
  4. Intake air leak skewing the mixture
  5. Mechanical problem in the cylinder, such as low compression
  6. ECM software or calibration issue (uncommon)

How to diagnose

  1. Scan all codes and freeze frame data, and look for misfire codes
  2. Review fuel trims and injector adaptation values on a scan tool
  3. Inspect the cylinder 5 injector connector and harness, including pins and ground
  4. Measure injector resistance and check the drive signal with a scope or noid light
  5. Test fuel pressure and how well it holds after shutdown
  6. Look for intake leaks, for example with a smoke machine
  7. Compare cylinder performance with an injector balance test and compression test
  8. Swap the injector with a neighbor and see whether the problem follows it

Common fixes

  • Professionally clean or replace the cylinder 5 injector
  • Repair the injector wiring and connector
  • Replace the fuel filter or fix the cause of low fuel pressure
  • Repair any intake air leak
  • Update the ECM software and reset adaptations if the manufacturer calls for it

Questions and answers

What does P02D5 mean?

The ECM can't correct fuel delivery from the cylinder 5 injector any further because the learned correction has reached its limit. It points to an injector, wiring, fuel pressure or cylinder problem.

Can I drive with P02D5?

Briefly and carefully until it's diagnosed. If you notice misfires or the light starts flashing, stop to protect the catalytic converter.

Will clearing the code fix it?

No. If the cause remains, the code will return. Find out why the injector needs such a large correction.

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.