U0168 Diagnostic Trouble Code

U0168 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 U0168 diagnostic trouble code may include:

The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Faulty PCM
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected
Diminished fuel efficiency

Possible Causes :

An air leak forward of the DPF will change the sensor readings resulting in the code
Rusty exhaust systems, cracked exhaust manifolds or damaged or missing gaskets or donuts will cause air leaks.
Fuel with a large percentage of sulfur will clog the DPF quickly

Repair Processes :

Once located, visually inspect the connectors and wiring. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. 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. Replace the oxygen sensor that is downstream from the catalytic converter on the side of the engine that does not contain cylinder #1. Also, if a oxygen sensor code stating "heater circuit malfunction" the sensor has most probably failed.

Process Tips

Diagnostic trouble code U0168 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 U0168.

Fortunately, U0168 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U0168 Trouble Code For Specific Cars

U0168 Saab 92
U0168 Chevrolet Citation Driver Rear Door Ajar Circuit Open
U0168 Mercedes Clk 430 ABS Outlet Valve Coil Rear Circuit Failure
U0168 Chevrolet Malibu 7 EEPROM Malfunction
U0168 Ginetta G21 Oil Temperature Sensor Circuit Failure
U0168 Proton Saga Flx Fuel System Leak Detected Small Leak
U0168 Gaz 3110 O2 Sensor Circuit Malfunction (Bank 2 Sensor 3)