Fuel and air

P02E3 — Diesel Intake Air Flow Control Circuit High

Severity: medium Drive with care, to a shop

What P02E3 means

The engine control module monitors the electrical circuit of the actuator that regulates airflow into a diesel's intake (an intake or throttle flap). P02E3 sets when voltage or signal in that circuit is higher than expected, for example from a short to power, an open circuit or a failed actuator. The ECM then can't meter intake air accurately.

Symptoms

  • Check Engine light on
  • Reduced power and sluggish acceleration
  • Rough idle
  • Stalling at idle or when lifting off the throttle
  • Higher fuel consumption
  • More exhaust smoke

Possible causes

  1. Failed intake air flow actuator (motor)
  2. Damaged wiring or a short to power
  3. Corroded or loose electrical connector
  4. Carbon-clogged or stuck flap overloading the actuator
  5. ECM fault (rare)

How to diagnose

  1. Read all codes and freeze frame data, and note any related airflow or boost codes
  2. Inspect the actuator harness and connector for chafing, heat damage, corrosion and moisture
  3. Check for power and ground at the actuator connector with a multimeter, following the factory wiring diagram
  4. Test the signal wire for a short to power or an open circuit
  5. Move the flap by hand and check it isn't coked up or binding
  6. Run an actuator test with a scan tool and compare commanded and actual position
  7. If wiring and actuator are good, check the ECM and its power supply

Common fixes

  • Repair damaged wiring or replace the connector
  • Clean the contacts and secure the connector
  • Clean carbon buildup from the flap
  • Replace the actuator or the flap assembly
  • Repair or reprogram the ECM (last resort)

Questions and answers

What does P02E3 mean?

The diesel ECM sees too high a signal in the circuit of the actuator that controls intake airflow. The actuator or its wiring is the most common culprit.

Can I drive with P02E3?

Only briefly and carefully, such as to a shop. Power is usually limited and the engine may stall, which is dangerous in traffic.

How do I fix P02E3 myself?

Start by inspecting the actuator wiring and connector and cleaning carbon off the flap. If that doesn't help, scan-tool testing is needed and the actuator will likely need replacing.

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.