U0038 Diagnostic Trouble Code

U0038 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 U0038 diagnostic trouble code may include:

Faulty O2 Sensor
Lack of power
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected
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 :

Defective ECU strategies or components will prevent proper regeneration
The Mass Airflow sensor is a hot wire that senses the volume of air entering the intake manifold. The computer uses this information to control fuel mixture.
Fuel with a large percentage of sulfur will clog the DPF quickly

Repair Processes :

With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground. 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.

Process Tips

Diagnostic trouble code U0038 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 U0038.

Fortunately, U0038 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U0038 Trouble Code For Specific Cars

U0038 Muntz Jet Camshaft Position Sensor B Range / Performance
U0038 Stanley 20 Lamp Keypad Output Short Circuit To Ground
U0038 Gmc Autonomy Park Brake Actuator Assembly Switch Applied Circuit Failure
U0038 Daihatsu Terios Glow Plug/Heater Circuit "B" Malfunction
U0038 Saturn L Immobilizer Code Word/ID Number Write Failure
U0038 Mazda 121 Transmission Transfer Case Contact Plate 'A' Short Circuit To Battery
U0038 Saturn Outlook Immobilizer/ECM Communication Error