U02A3 Diagnostic Trouble Code

U02A3 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 U02A3 diagnostic trouble code may include:

Engine surge
Blown fuse (if applicable)
Lack of power
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)
Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)

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. 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 U02A3 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 U02A3.

Fortunately, U02A3 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U02A3 Trouble Code For Specific Cars

U02A3 Brutsch V2n Cruise Control/Brake Switch A Circuit High
U02A3 Honda Shuttle Remote Keyless Entry Out of Synchronization
U02A3 Vauxhall Nova Pressure Control Solenoid B Performance
U02A3 Mercedes-benz Bionic Air Conditioner Refrigerant Charge Loss
U02A3 Maserati Boomerang Transmission Fluid Pressure Sensor/Switch C Circuit Intermittent
U02A3 Nissan Lucino Column Tilt Feedback Potentiometer Circuit Short to Battery
U02A3 Crossley Shelsley Fuel Tank Pressure Sensor Circuit Failure