P1D66 Diagnostic Trouble Code

P1D66 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 P1D66 diagnostic trouble code may include:

Possible spark knock (detonation / pre-ignition)
Poor fuel economy
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
Rich or lean exhaust

Possible Causes :

The Mass Airflow sensor will also cause this problem. Mass Airflow circuit malfunction.
Fuel with a large percentage of sulfur will clog the DPF quickly
Defective ECU strategies or components will prevent proper regeneration

Repair Processes :

Look for damage to the tank indicating impact that may have damaged the fuel pump or sender. 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. Use the DVOM to test resistance and continuity on all system circuits if actuator and sensor resistance levels are in compliance with manufacturer's specifications.

Process Tips

Diagnostic trouble code P1D66 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 P1D66.

Fortunately, P1D66 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P1D66 Trouble Code For Specific Cars

P1D66 Wolseley 25
P1D66 Seat Malaga Injector High Side Open - Bank 2/Target idle not reached
P1D66 Gaz 27 O2 Sensor Circuit Malfunction (Bank 1 Sensor 1)
P1D66 Fiat 1t Lack Of HO2S21 Switch - Sensor Indicates Rich
P1D66 Allard V Air Bag Driver/Passenger Circuit Short To Ground
P1D66 Hyundai Accent RPM Input Circuit Failure
P1D66 Buick 70 Cylinder 4 Injector Circuit Low