P078E Diagnostic Trouble Code

P078E 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 P078E diagnostic trouble code may include:

Carbon Buildup on O2 Sensor
Malfunction Indicator Lamp (MIL) illuminated
Hesitation upon acceleration
The engine oil will exhibit dilution from the ECUs attempts to increase engine temperature. Some vehicles advance the fuel injection timing slightly after top center to afterburn a small amount of fuel to increase exhaust temperatures. Some of this fuel enters the crankcase. When the ECU determines the necessity to regenerate the DPF, the service life of the oil be shortened significantly

Possible Causes :

A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.
Faulty IMRC actuator/sensor
Some aftermarket accessories and performance modifications

Repair Processes :

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. 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 damage to the tank indicating impact that may have damaged the fuel pump or sender.

Process Tips

Diagnostic trouble code P078E 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 P078E.

Fortunately, P078E is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P078E Trouble Code For Specific Cars

P078E Siata Amica Intake Air Temperature Sensor 2 Circuit Low
P078E Mitsubishi Model A Aux A/C Control Switch Reference Circuit Short to Ground
P078E Marcos Gts Transfer Case unable to transition between 2H and 4H
P078E Bmw L Clutch Actuator Circuit High
P078E Vauxhall Vectra C Pressure Control Solenoid C Stuck On
P078E Volkswagen Fox Ride Control LF Shock Actuator Circuit Short To Battery
P078E Ifa F9