P156D Diagnostic Trouble Code

P156D 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 P156D diagnostic trouble code may include:

Faulty or damaged wiring
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
Poor fuel economy
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected

Possible Causes :

A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
Faulty IMRC actuator relay (if equipped)
A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.

Repair Processes :

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 missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector. Look at the plug wires to make sure they are not burnt or laying on the exhaust.

Process Tips

Diagnostic trouble code P156D 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 P156D.

Fortunately, P156D is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P156D Trouble Code For Specific Cars

P156D Peel Trident Driver's Door Unlock Relay Circuit Short to Battery
P156D Toyota Corsa O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 3)
P156D Nissan Primera Crankshaft Position Camshaft Position Correlation (Bank 1 Sensor B)
P156D Lancia Augusta Speed Wheel Sensor LF Input Circuit Failure
P156D Calthorpe 12 Door Ajar Circuit Open
P156D Lotus Evora Traction Control Motor Circuit Short to Battery
P156D Maxwell Model Dr. Transmission Range Sensor Circuit Low Input