C0520 Diagnostic Trouble Code

C0520 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 C0520 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 :

Faulty IMRC actuator/sensor
A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.
An air leak forward of the DPF will change the sensor readings resulting in the code

Repair Processes :

If you find a related TSB, the information will often help in diagnosing the code in question as TSBs are crested from many thousands of repairs. Find out what kind of system you have and verify that voltage to the fuel level sensor is present at the fuel pump wiring harness.

Process Tips

Diagnostic trouble code C0520 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 C0520.

Fortunately, C0520 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C0520 Trouble Code For Specific Cars

C0520 Jaguar C-type Seat Driver Forward Circuit Open
C0520 Rolls-royce Silver Dawn IAT - B Circuit Malfunction/ Exhaust Gas Recirculation Closed Position Performance
C0520 Maserati Mistral Transmission Fluid Pressure Sensor/Switch F Circuit Range/Performance
C0520 Talbot Samba Mirror Passenger Left Circuit Open
C0520 Bmw 5 Chime Input Request Circuit Failure
C0520 Abarth Bialbero A/C Clutch Circuit Fault
C0520 Peugeot 504 EIC Switch-2 Assembly Circuit Open