C0479 Diagnostic Trouble Code

C0479 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 C0479 diagnostic trouble code may include:

The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Faulty PCM
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected
Diminished fuel efficiency

Possible Causes :

The Mass Airflow sensor is a hot wire that senses the volume of air entering the intake manifold. The computer uses this information to control fuel mixture.
Defective ECU strategies or components will prevent proper regeneration
An air leak forward of the DPF will change the sensor readings resulting in the code

Repair Processes :

Look at the plug wires to make sure they are not burnt or laying on the exhaust. 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. If all testing has passed so far yet you still have the same code, check your scan tool and see if it can open and close the IMRC valve.

Process Tips

Diagnostic trouble code C0479 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 C0479.

Fortunately, C0479 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C0479 Trouble Code For Specific Cars

C0479 Saab 9-2
C0479 Paramount Ten Driver Side Crash Sensor Internal Fault
C0479 Panhard Pl Driver Power Window Up Circuit Open
C0479 Plymouth Reliant Evaporative System Vacuum Test Malfunction
C0479 Chrysler Newport Evaporative Emission Control System Vent Control Circuit Shorted
C0479 Subaru Impreza 2 Left Rear Center Sensor Circuit Short to Vbat
C0479 Saturn Relay IMRC Input Error (Bank 1)