P0C18 Diagnostic Trouble Code

P0C18 is a kind of OBD-II Diagnostic P-Powertrain 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 P0C18 diagnostic trouble code may include:

Faulty or damaged wiring
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
Poor fuel economy
Hesitation upon acceleration

Possible Causes :

Some aftermarket accessories and performance modifications
A faulty oxygen sensor. This will set a code in itself, however, a faulty oxygen sensor does not automatically condemn the sensor. The code just means that the sensor signal was not within specifications. An air leak or any of the above will cause an erroneous signal. There is a multitude of O2 codes relating to O2 performance which gives a clue to the problematic area.
A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.

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. 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 P0C18 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 P0C18.

Fortunately, P0C18 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P0C18 Trouble Code For Specific Cars

P0C18 Vemac Rd PSPS Out Of Self Test Range
P0C18 Cadillac 6.5 Hp Damper RF Circuit Failure
P0C18 Citroen C4 Aircross FTS High - Fuel Pump Temperature Sensor High
P0C18 Panther Six Driver Sid, Side mount Airbag Low resistance on Squib
P0C18 Holden Lj Power Steering Pressure Sensor Circuit Malfunction
P0C18 Buick Invicta Cylinder 8 Contribution/Balance Fault
P0C18 Smyjk 350 Lamp Backup Switch Input Circuit Failure