C3420 Diagnostic Trouble Code

C3420 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 C3420 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
Reduction in engine performance, especially at low RPM levels

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.
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. You might continue by connecting the scanner to the vehicle diagnostic connector and retrieving all stored codes and freeze frame data. 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.

Process Tips

Diagnostic trouble code C3420 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 C3420.

Fortunately, C3420 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C3420 Trouble Code For Specific Cars

C3420 Bmw S3 Clutch Position Control Error
C3420 Suzuki Swift Mirror Driver Right Circuit Short To Battery
C3420 Mazda Cx-5 Transmission Transfer Case Front Shaft Speed Sensor Circuit Failure
C3420 Minerva 30 Anti Theft Input Signal Circuit Failure
C3420 Seat Cordoba Injector Circuit Open / Shorted - Cylinder #4
C3420 Chrysler Expresso Evaporative Emission (EVAP) System Flow During Non-Purge Chevrolet Only
C3420 Panhard 120 Driver Power Window Down Circuit Open