C12F4 Diagnostic Trouble Code

C12F4 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 C12F4 diagnostic trouble code may include:

Carbon Buildup on O2 Sensor
Malfunction Indicator Lamp (MIL) illuminated
Hesitation upon acceleration
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.

Possible Causes :

An air leak forward of the DPF will change the sensor readings resulting in the code
Rusty exhaust systems, cracked exhaust manifolds or damaged or missing gaskets or donuts will cause air leaks.
Some aftermarket accessories and performance modifications

Repair Processes :

Once located, visually inspect the connectors and wiring. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. If the engine displays a miss and there wasn't a code, determine which cylinder is misfiring. If the exhaust manifold is visible, spay or pour a small amount of water on each cylinder exhaust port. Water will evaporate immediately on good cylinders and slowly on the missing cylinder. If this can't be accomplished pull the plugs and check the condition. Look for damage to the tank indicating impact that may have damaged the fuel pump or sender.

Process Tips

Diagnostic trouble code C12F4 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 C12F4.

Fortunately, C12F4 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C12F4 Trouble Code For Specific Cars

C12F4 Rover 25 Ignition Coil - Cylinder 3 - Early Activation Fault
C12F4 Mazda 323 Transmission Transfer Case Contact Plate 'C' Circuit Failure
C12F4 Ford Cougar Main Catalyst Efficiency Below Threshold (Bank 1)
C12F4 Citroen Lna Fuel Pump Low Speed Malfunction
C12F4 Jeep Jeepster Seat Driver Rearward Switch Circuit Failure
C12F4 Lamborghini Espada Shift Time Too Short
C12F4 Peugeot Tepee Engine Oil Pressure Sensor/Switch Low Voltage