Technical Definition:
Exhaust Gas Recirculation (EGR) Flow Excessive Detected
Trouble Code: P0402
Address: 0x0402
System: Powertrain
Subsystem: Auxiliary Emission Controls
Address: 0x0402
System: Powertrain
Subsystem: Auxiliary Emission Controls
Technical Description:
EGR stands for Exhaust Gas Recirculation. It is part of the vehicle emmissions system, and is used to reduce combustion temperature and pressure to control Oxides of Nitrogen.
Possible Causes:
- DPFE (differential pressure) sensor is faulty and needs to be replaced
- There is a blockage in the EGR (most likely carbon buildup)
- EGR valve fault
- EGR valve may not be opening due to a lack of vaccuum
Possible Symptoms:
Exhaust Gas Recirculation Flow Excessive Detected
Possible Solutions:
- Check the voltage at the DPFE sensor both at idle and when the EGR is open
- Replace the DPFE sensor
OBD-II Trouble Code Type:
Diagnostic Step:
Tech Notes:
– EGR volume control valve stuck open
– Faulty EGR volume control valve
– EGR solenoid valve harness is open or shorted
– EGR solenoid valve circuit poor electrical connection
– Faulty EGR temperature sensor and circuit
Specific Makes:
– Possible engine hesitation