C120E Diagnostic Trouble Code

C120E 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 C120E diagnostic trouble code may include:

Diminished fuel efficiency
Fuel pressure too high
Malfunction Indicator Lamp (MIL) illuminated
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected

Possible Causes :

Fuel with a large percentage of sulfur will clog the DPF quickly
The Mass Airflow sensor will also cause this problem. Mass Airflow circuit malfunction.
Faulty IMRC actuator/sensor

Repair Processes :

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. Look at the plug wires to make sure they are not burnt or laying on the exhaust. 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.

Process Tips

Diagnostic trouble code C120E 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 C120E.

Fortunately, C120E is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C120E Trouble Code For Specific Cars

C120E Sunbeam 14 Main Blower Motor Relay Circuit Short to Battery
C120E Kia Rio Ii Secondary Air Injection System Relay A circuit Malfunction
C120E Aston Martin V8 Air Suspension Warning Lamp Circuit Short To Battery
C120E Porsche 930 Fuel Demand Command Signal Circuit Malfunction
C120E Ds Ds 4 Ignition/Distributor Engine Speed Input Circuit Intermittent
C120E Dacia Sandero Ii Fuel Temperature Sensor B Circuit Intermittent
C120E Bristol 412 Crankshaft Position Camshaft Position Correlation (Bank 2 Sensor B)