U0026 Diagnostic Trouble Code

U0026 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 U0026 diagnostic trouble code may include:

Faulty or damaged wiring
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
Poor fuel economy
Rich or lean exhaust

Possible Causes :

Faulty IMRC actuator relay (if equipped)
A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.

Repair Processes :

If all testing has passed so far yet you still have the same code, check your scan tool and see if it can open and close the IMRC valve. Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector. Look at the plug wires to make sure they are not burnt or laying on the exhaust.

Process Tips

Diagnostic trouble code U0026 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 U0026.

Fortunately, U0026 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P1205 Trouble Code For Specific Cars

U0026 Opel Astra H DC-DC Converter Failure
U0026 Ferrari 275 Input/Turbine Speed Sensor Circuit Range/Performance
U0026 Mitsubishi Dion Autolamp Delay Circuit Failure
U0026 Jaguar Xj-12 Seat Driver Front Up Circuit Short To Ground
U0026 Riley One-point-five Hydraulic Clutch Actuator Valve Circuit Failure
U0026 Peugeot Sesame Engine Oil Pressure Sensor/Switch High Voltage
U0026 Tamplin 8 Mirror Passenger Up Circuit Open