U147D Diagnostic Trouble Code

U147D is a kind of OBD-II Diagnostic U-Network 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 U147D 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
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.

Possible Causes :

An air leak forward of the DPF will change the sensor readings resulting in the code
Rusty exhaust systems, cracked exhaust manifolds or damaged or missing gaskets or donuts will cause air leaks.
Defective ECU strategies or components will prevent proper regeneration

Repair Processes :

Pack the connector cavity with dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and reassemble. 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. Look for damage to the tank indicating impact that may have damaged the fuel pump or sender.

Process Tips

Diagnostic trouble code U147D 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 U147D.

Fortunately, U147D is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U147D Trouble Code For Specific Cars

U147D Pontiac Pathfinder Fan Secondary High With Fan(s) Off
U147D Mg Rover Air Temperature External Sensor Circuit Failure
U147D Mercedes Sl 400 Air Bag Crash Sensor #2 Feed/Return Circuit Open
U147D Nissan Gloria Clutch Position Sensor Circuit Low Malfunction
U147D Lotus 79 Torque Converter/Brake Switch B Circuit Low
U147D Toyota Hilux Oil Level Lamp Circuit Open
U147D Chevrolet Venture Engine Coolant Temperature (ECT) Sensor Circuit Intermittent Low Voltage/IAT - B Circuit Low Input