C0422 Diagnostic Trouble Code

C0422 is a kind of OBD-II Diagnostic C-Chassis Diagnostic Trouble Code.

It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.

Symptoms

Symptoms of a C0422 diagnostic trouble code may include:

Fuel pressure too low
Rich or lean exhaust
Diminished fuel efficiency
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected

Possible Causes :

A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
Faulty IMRC actuator relay (if equipped)
Faulty IMRC actuator/sensor

Repair Processes :

If the scan tool has that capability, and the scan tool can operate the IMRC valves, then the problem is either resolved and a simple code clearing is all that's left or a new PCM would be called for. Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector. Replace the oxygen sensor that is downstream from the catalytic converter on the side of the engine that does not contain cylinder #1. Also, if a oxygen sensor code stating "heater circuit malfunction" the sensor has most probably failed.

Process Tips

Diagnostic trouble code C0422 is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before C0422.

Fortunately, C0422 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C0422 Trouble Code For Specific Cars

C0422 Mazda Grand TSS Circuit Intermittent Malfunction
C0422 Citroen C4 Front Wiper Select Switch "W" Short to Ground
C0422 Zaz Tavrija
C0422 Turner Gt Pedal Position Sensor Disagreement btwn Sensors
C0422 Suzuki Verona Mirror Driver Up Circuit Open
C0422 Fpv Bf Multi-faults - Bank 1 - With Low Side Shorts
C0422 Morgan Aero B-pillar Power Sliding Door Open/Close Switch Input Ckt Short to Gnd