Fuel and air

P02EF — Cylinder 2 Injector Circuit Range/Performance

Severity: medium Drive with care, to a shop

What P02EF means

The engine control module monitors the electrical circuit that drives the cylinder 2 fuel injector and compares its behavior with what it expects. P02EF is stored when the circuit readings or injector response fall outside the allowed range. The cause may be the injector itself, its wiring or connector, or, rarely, the driver inside the ECM.

Symptoms

  • Check Engine Light on
  • Rough idle or misfire on cylinder 2
  • Reduced power and sluggish acceleration
  • Worse fuel economy
  • Hard starting
  • Engine vibration under load

Possible causes

  1. Faulty or sticking cylinder 2 fuel injector
  2. Corroded, damaged or loose injector connector
  3. Open or short in the injector wiring harness
  4. High resistance in the injector circuit
  5. Failed injector driver in the ECM (rare)
  6. Fuel supply problem or air leak skewing the mixture

How to diagnose

  1. Scan all codes and freeze-frame data and look for other cylinder-related codes
  2. Inspect the cylinder 2 injector connector and harness for corrosion, chafing and a secure fit
  3. Measure injector coil resistance and compare with the spec for your engine
  4. Check for power and the control signal at the connector with a noid light or scope
  5. Test the wiring to the ECM for opens, shorts to power and shorts to ground
  6. Swap injectors between cylinders to see if the fault follows the injector
  7. Check fuel pressure and fuel trim values
  8. Rule out intake air leaks

Common fixes

  • Repair the wiring or replace the damaged connector
  • Clean or replace the cylinder 2 injector
  • Replace the faulty injector
  • Reflash or replace the ECM if a driver fault is confirmed

Questions and answers

What does P02EF mean?

It is a cylinder 2 injector circuit fault: the ECM sees electrical values or injector behavior outside the normal range. Start with the wiring and connector, then test the injector.

Can I drive with code P02EF?

Only briefly, for example to a shop. Misfires can damage the catalytic converter, and a wrong mixture in one cylinder can harm the engine.

Do I always need a new injector?

No. Connectors and wiring are common causes, so test the circuit and injector resistance first and replace the injector only once it is confirmed faulty.

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.