P078A Diagnostic Trouble Code

P078A 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 P078A diagnostic trouble code may include:

Misfire
Misfire
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Diminished fuel efficiency

Possible Causes :

Faulty IMRC actuator/sensor
A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.
An air leak forward of the DPF will change the sensor readings resulting in the code

Repair Processes :

Once located, visually inspect the connectors and wiring. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. 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 damage to the tank indicating impact that may have damaged the fuel pump or sender.

Process Tips

Diagnostic trouble code P078A 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 P078A.

Fortunately, P078A is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P078A Trouble Code For Specific Cars

P078A Toyota 4500 No Communication to TV Module (No Fitting of TV)
P078A Lamborghini Gallardo Shift/Timing Solenoid Intermittent
P078A Bond Equipe Control Module Long Term Memory Performance/ Immobilizer Code Words Do Not Match
P078A Panther Lima Driver Sid, Side mount Airbag Circuit Short to Ground
P078A Marcos Gts Transfer Case unable to transition between 2H and 4H
P078A Chevrolet Monte Carlo EGI Temperature Sensor Failure
P078A Cadillac Park Avenue Dim Panel Increase Input Circuit Failure