P0403 – Exhaust Gas Recirculation Circuit Malfunction

Meaning:

When the PCM has detected that the EGR circuit has malfunctioned, the P0403 happens
The P0403 is triggered when the PCM has detected that the EGR circuit has malfunctioned

The PCM has detected that the EGR circuit has malfunctioned and isn’t sending the proper voltage at the proper time.

Main Symptoms:

Possible Causes:

  • Short or open in circuit leading to EGR solenoid
  • Pins connecting EGR solenoid are worn out or loose
  • Presence of water in EGR solenoid harness
  • EGR solenoid isn’t getting voltage supply

Diagnostic Steps:

  • Pull codes and freeze frame data to confirm P0403 code
  • Check all wiring and connections to EGR solenoid
  • Disconnect and check EGR valve circuit for a short or open
  • Clear code and do test drive. If it comes back replace solenoid

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