U0315 Diagnostic Trouble Code

U0315 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 U0315 diagnostic trouble code may include:

Fuel pressure too low
Rich or lean exhaust
Diminished fuel efficiency
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)
Faulty IMRC actuator/sensor

Repair Processes :

Once located, visually inspect the connectors and wiring. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. 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.

Process Tips

Diagnostic trouble code U0315 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 U0315.

Fortunately, U0315 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U0315 Trouble Code For Specific Cars

U0315 Datsun 1200 Heater Coolant Temp sensor circuit Short to GND
U0315 Koenigsegg Ccxr Servo Motor Potentiometer Coolair Circuit Short To Ground
U0315 Vauxhall Astra H Powertrain Performance Mode Switch Circuit failure
U0315 Volkswagen Iltis Right Front Center Sensor Circuit Fault
U0315 Locomobile Junior Timing Reference High Resolution Signal A Too Many Pulses
U0315 Land Rover Discovery 2 Steering Column Switch Circuit Short to Battery
U0315 Vanden Plas Limousine Power Window Master Circuit Open