U1158 Diagnostic Trouble Code

U1158 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 U1158 diagnostic trouble code may include:

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
Faulty or damaged wiring
Hesitation upon acceleration
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)
Defective ECU strategies or components will prevent proper regeneration

Repair Processes :

It should be pretty close to battery voltage (12 volts). If not, then this is the circuit that has the problem. 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 U1158 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 U1158.

Fortunately, U1158 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U1158 Trouble Code For Specific Cars

U1158 Renault Kadjar Glow Plug/Heater Circuit "B" Malfunction
U1158 Avanti Avanti Aux Heater Glow Plug Circuit Short to Ground
U1158 Austin 12 Audio Reverse Aid Mute Input Ckt Failure
U1158 Ford S-max Mirror Passenger Right Circuit Short To Ground
U1158 Holden Td Power Window LR Motor Circuit Short To Ground
U1158 Mazda Az Transmission Transfer Case Counter Clockwise Shift Relay Coil Open Circuit
U1158 Amc Rambler Air Suspension Gate Solenoid Output Circuit Short To Battery