U2UAC Diagnostic Trouble Code

U2UAC 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 U2UAC diagnostic trouble code may include:

Excessive exhaust leak
Hesitation upon acceleration
Malfunction Indicator Lamp (MIL) illuminated
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.
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.

Repair Processes :

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. 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.

Process Tips

Diagnostic trouble code U2UAC 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 U2UAC.

Fortunately, U2UAC is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U2UAC Trouble Code For Specific Cars

U2UAC Hyundai I40
U2UAC Weber Sportscars F1 SCP (J1850) Invalid or Missing Data for Mirrors
U2UAC Mercedes-benz 190 Air Bag Memory Clear Circuit Open
U2UAC Ascari Fg-t Air Suspension RF Air Spring Solenoid Output Circuit Failure
U2UAC Porsche 924 Fuel Delivery System Malfunction - High
U2UAC Chery V5 Drive Switch Input Circuit High
U2UAC Mercedes-benz Clk Class Air Suspension Compressor Relay Circuit Failure