B251F Diagnostic Trouble Code

B251F 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 B251F diagnostic trouble code may include:

Faulty O2 Sensor
Lack of power
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected
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.
Fuel with a large percentage of sulfur will clog the DPF quickly

Repair Processes :

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 missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector. Pack the connector cavity with dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and reassemble.

Process Tips

Diagnostic trouble code B251F 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 B251F.

Fortunately, B251F is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

B251F Trouble Code For Specific Cars

B251F Ssangyong Chairman LAMP DOME OUTPUT Circuit Short to Battery
B251F Frazer Nash Shelsley NVM Configuration Failure
B251F Abarth Ot A/C Evaporator Air Temperature Circuit Low
B251F Chrysler Howler Evaporative Emission Control System leak Detected (small leak)
B251F Mercedes B 150 ABS Hydraulic Pressure Differential Switch Input Circuit Failure
B251F Cadillac Allante Damper RR Circuit Open
B251F Cadillac Osceola Dim Panel Decrease Input Circuit Short To Ground