P1402 EGR Function Open

OBD-II Code P1402: This code indicates that there is an issue with the Exhaust Gas Recirculation (EGR) system, specifically that it is stuck in the open position. The EGR system helps reduce nitrogen oxide emissions by recirculating a portion of the exhaust gases back into the engine cylinders.

P1402 – EGR Function Open

Typical Severity: Moderate

Common Causes

P1402 EGR Function Open

Common Causes:

• Faulty EGR valve
• Clogged EGR passages
• Vacuum leak in the EGR system
• Wiring or connector issues in the EGR circuit
• ECU/PCM software issue related to EGR function

 

Common Misdiagnosis

OBD2 Code: P1402

Description: EGR Function Open

Common Misdiagnosis: Replacing the EGR valve without checking for vacuum leaks or issues with the EGR solenoid and related wiring.

 

Common Diagnostic Steps

OBD2 Code: P1402

Description: EGR Function Open

• Check for any additional trouble codes that may be present.
• Inspect the EGR valve and its components for damage or wear.
• Verify that the EGR valve is not stuck open due to carbon buildup or debris.
• Test the vacuum supply to the EGR valve if applicable.
• Examine electrical connections and wiring related to the EGR system for corrosion or damage.
• Use a scan tool to monitor EGR operation and ensure it matches manufacturer specifications.
• If equipped, check the function of the EGR position sensor using a multimeter or scan tool data stream.
• Perform a smoke test to identify any vacuum leaks in the intake manifold or associated hoses.
• If necessary, replace faulty components such as the EGR valve, solenoid, or position sensor based on diagnostic findings.