P278A Diagnostic Trouble Code

P278A 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 P278A diagnostic trouble code may include:

Corroded or damaged connector
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected
Lack of power
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.

Possible Causes :

Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.
Rough running engine due to misfiring plugs. Many engines have misfire codes to indicate the cylinder effected, such as P0307 for number 7.

Repair Processes :

Find out what kind of system you have and verify that voltage to the fuel level sensor is present at the fuel pump wiring harness. 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. You might continue by connecting the scanner to the vehicle diagnostic connector and retrieving all stored codes and freeze frame data.

Process Tips

Diagnostic trouble code P278A 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 P278A.

Fortunately, P278A is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P278A Trouble Code For Specific Cars

P278A Iso Grifo SCP (J1850) Invalid or Missing Data for Primary Id / Vehicle Speed
P278A Pontiac Ventura Front Crash Sensor Mount Fault
P278A Citroen C2 Front Wiper Motor Relay Circuit Open (changed from Failure 2/6/97)
P278A Datsun Bluebird HO2S Heater Control Circuit (Bank 1 Sensor 1)
P278A Alfa Romeo Eagle Adaptive Mode Switch Circuit Failure
P278A Volvo 142
P278A Fnm 2150 Left Rear Stop lamp Circuit Short to Battery