P249B Diagnostic Trouble Code

P249B 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 P249B diagnostic trouble code may include:

Poor acceleration
Cherry red hot catalytic converter
Possible spark knock (detonation / pre-ignition)
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 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.

Repair Processes :

Check to make sure they are not burnt or corroded. If in doubt, get some Electrical Contact cleaner at any parts store if cleaning of the terminals is needed. 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.

Process Tips

Diagnostic trouble code P249B 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 P249B.

Fortunately, P249B is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P249B Trouble Code For Specific Cars

P249B Brasinca 4200 Convertible Top Up/Down switch Fault
P249B Volkswagen Polo Rotor Calibration Fault
P249B Rover 2600 Ignition Coil - Cylinder 5 - Early Activation Fault
P249B Ford Zx2 Motor Temperature Out of Range
P249B Jeep Compass 2 Seat Driver Rear Up Switch Circuit Failure
P249B Mercedes C 63 ABS Inlet Valve Coil Rear Circuit Failure
P249B Ford Rs Mirror Passenger Left Circuit Short To Ground