B25A9 Diagnostic Trouble Code

B25A9 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 B25A9 diagnostic trouble code may include:

The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Faulty PCM
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected
Reduction in engine performance, especially at low RPM levels

Possible Causes :

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.
Some aftermarket accessories and performance modifications
An air leak forward of the DPF will change the sensor readings resulting in the code

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. 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 B25A9 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 B25A9.

Fortunately, B25A9 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

B25A9 Trouble Code For Specific Cars

B25A9 Isuzu Zxs
B25A9 La Buire 10 Hp Servo Motor Potentiometer Foot Circuit Open
B25A9 Innocenti C
B25A9 Packard 200 DPFE Circuit High Input
B25A9 Lada 2123 Shift Solenoid A Performance or Stuck Off/1-2 Shift Solenoid Valve Performance
B25A9 Brewster Brewster Coolant Temp Out of Range
B25A9 Syrena Fso Mirror Driver/Passenger Switch Circuit Short To Battery