B278D Diagnostic Trouble Code

B278D 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 B278D 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
Diminished fuel efficiency

Possible Causes :

An air leak forward of the DPF will change the sensor readings resulting in the code
Rusty exhaust systems, cracked exhaust manifolds or damaged or missing gaskets or donuts will cause air leaks.
Fuel with a large percentage of sulfur will clog the DPF quickly

Repair Processes :

Pack the connector cavity with dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and reassemble. 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 B278D 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 B278D.

Fortunately, B278D is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

B278D Trouble Code For Specific Cars

B278D Suzuki Xl-6 Mirror Driver Vertical Switch Circuit Open
B278D Toyota Vanguard Passenger Power Window Motor Circuit Short To Ground
B278D Chrysler Aspen Engine Oil Temperature Sensor Malfunction
B278D Chrysler Pacifica Evaporative Emission Control System Vent Valve/Solenoid Circuit Malfunction
B278D Armstrong Siddeley Whitley Air Suspension Rear Height Sensor Low Signal Circuit Open
B278D Lti Tx Traction Control Valve LF Circuit Failure
B278D Fiat 127 Knock Sensor 1 Circuit Malfunction (Bank 1 or Single Sensor)