C0127 Diagnostic Trouble Code

C0127 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 C0127 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 :

A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
Faulty IMRC actuator relay (if equipped)
An air leak forward of the DPF will change the sensor readings resulting in the code

Repair Processes :

Check to make sure they are not burnt or corroded. If in doubt, get some Electrical Contact cleaner at any parts store if cleaning of the terminals is needed. With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground.

Process Tips

Diagnostic trouble code C0127 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 C0127.

Fortunately, C0127 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C0127 Trouble Code For Specific Cars

C0127 Ds Ds 5 Ignition/Distributor Engine Speed Input Circuit Malfunction
C0127 Porsche 917 Fuel Composition Sensor Circuit Range/Performance
C0127 Fiat 25 Lamp ABS Warning Output Circuit Short To Battery
C0127 Nissan Laurel Column Reach Feedback Potentiometer Circuit Open
C0127 Steyr Type 220 Lamp Turn Signal Front Output Circuit Open
C0127 Ford Econovan MAP/MAF Throttle Position Correlation
C0127 Holden Jb Power Sliding Door Override Switch Input Ckt Short to Gnd