C120C Diagnostic Trouble Code

C120C 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 C120C diagnostic trouble code may include:

Vacuum leak on the engine
Reduction in engine performance, especially at low RPM levels
Engine surge
Rich or lean exhaust

Possible Causes :

The Mass Airflow sensor will also cause this problem. Mass Airflow circuit malfunction.
Fuel with a large percentage of sulfur will clog the DPF quickly
Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)

Repair Processes :

Look for damage to the tank indicating impact that may have damaged the fuel pump or sender. 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 C120C 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 C120C.

Fortunately, C120C is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C120C Trouble Code For Specific Cars

C120C Opel Rekord Door Ajar RR Circuit Short To Battery
C120C Chevrolet Sabia EIC Switch-2 Assembly Circuit Open
C120C Cadillac Model D Dim Panel Decrease Input Circuit Short To Battery
C120C Holden Vt Pressure Control Solenoid "B" Short Circuit
C120C Vauxhall Viva Pressure Control Solenoid Stuck On
C120C Renault Sport Spider HO2S Heater Control C ircuit (Bank 1 Sensor 2)
C120C Opel Crossland X Digital TRS Failed to Transition States in KOEO / KOER