U12AE Diagnostic Trouble Code

U12AE 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 U12AE diagnostic trouble code may include:

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

Repair Processes :

Pack the connector cavity with dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and reassemble. 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. If the engine displays a miss and there wasn't a code, determine which cylinder is misfiring. If the exhaust manifold is visible, spay or pour a small amount of water on each cylinder exhaust port. Water will evaporate immediately on good cylinders and slowly on the missing cylinder. If this can't be accomplished pull the plugs and check the condition.

Process Tips

Diagnostic trouble code U12AE 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 U12AE.

Fortunately, U12AE is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U12AE Trouble Code For Specific Cars

U12AE Bmw X4 Column Reach Feedback Potentiometer Circuit Open
U12AE Zagato Bravo
U12AE Ferrari 355 Intake Air Temperature Circuit Intermittent
U12AE Opel Ascona Damper RR Circuit Short to Ground
U12AE Ford Expedition Memory 1 Switch Circuit Open
U12AE Daf 55 Gear Lever X Position Circuit Intermittent
U12AE Peugeot 508 Ii ELC System 2 Fault