U0338 Diagnostic Trouble Code

U0338 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 U0338 diagnostic trouble code may include:

Diminished fuel efficiency
Fuel pressure too high
Malfunction Indicator Lamp (MIL) illuminated
Misfire

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.
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.

Repair Processes :

You might continue by connecting the scanner to the vehicle diagnostic connector and retrieving all stored codes and freeze frame data. Look for damage to the tank indicating impact that may have damaged the fuel pump or sender.

Process Tips

Diagnostic trouble code U0338 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 U0338.

Fortunately, U0338 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U0338 Trouble Code For Specific Cars

U0338 Seat Ibiza Injector Control Pressure Above Expected Level
U0338 Hyundai Getz
U0338 Lexus Es TCM Power Input Signal Intermittent
U0338 Mercedes E 220 ABS Power Relay Coil Open Circuit
U0338 Checker Superba Door Passenger Set Switch Stuck Failure
U0338 Lancia Lybra Speed Wheel Sensor RR Input Open Circuit
U0338 Apperson Special Air Suspension LR Air Spring/Shock Solenoid Output Circuit Failure