B2172 Diagnostic Trouble Code

B2172 is a kind of OBD-II Diagnostic B-Body 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 B2172 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
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected

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)
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 :

You might continue by connecting the scanner to the vehicle diagnostic connector and retrieving all stored codes and freeze frame data. 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. 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 B2172 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 B2172.

Fortunately, B2172 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

B2172 Trouble Code For Specific Cars

B2172 Mercedes C Class ABS Inlet Valve Coil Rear Circuit Open
B2172 Opel Speedster Door Driver Set Switch Stuck Failure
B2172 Nissan 211 Chime Input Request Circuit Failure
B2172 Dodge Daytona Ignition Coil K Primary/Secondary Circuit Malfunction
B2172 Ac Aceca ABS Acceleration Switch Circuit Failure
B2172 Ats Gt Air Temperature Internal Sensor Circuit Short To Battery
B2172 Alfa Romeo 8c Accelerometer Rear Circuit Failure