C0301 Diagnostic Trouble Code

C0301 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 C0301 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
The engine oil will exhibit dilution from the ECUs attempts to increase engine temperature. Some vehicles advance the fuel injection timing slightly after top center to afterburn a small amount of fuel to increase exhaust temperatures. Some of this fuel enters the crankcase. When the ECU determines the necessity to regenerate the DPF, the service life of the oil be shortened significantly

Possible Causes :

Defective ECU strategies or components will prevent proper regeneration
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.
An air leak forward of the DPF will change the sensor readings resulting in the code

Repair Processes :

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. Pack the connector cavity with dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and reassemble. Oxygen sensors signal the engine management computer the amount of oxygen present in the exhaust, which is used in determining and controlling the fuel ratio.

Process Tips

Diagnostic trouble code C0301 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 C0301.

Fortunately, C0301 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C0301 Trouble Code For Specific Cars

C0301 Buick Enclave Cylinder 7 Injector Circuit High
C0301 Lotus Exige S3 Traction Control Motor Potentiometer Circuit Failure
C0301 Renault Espace Gear Shift position short to battery
C0301 Volvo 1500 SCP (J1850) Invalid or Missing Data for Climate Control (HVAC)
C0301 Ferrari 288 Input-shaft-speed input circuit failure
C0301 Marmon 34 Transmission 4-Wheel Drive Low Indicator Open Circuit
C0301 Mercedes C 180 ABS Hydraulic Pump Motor Circuit Short To Battery