U284A Diagnostic Trouble Code

U284A 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 U284A diagnostic trouble code may include:

Hesitation upon acceleration
Excessive exhaust leak
Rich or lean exhaust
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.
Some aftermarket accessories and performance modifications

Repair Processes :

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. Pack the connector cavity with dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and reassemble.

Process Tips

Diagnostic trouble code U284A 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 U284A.

Fortunately, U284A is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U284A Trouble Code For Specific Cars

U284A Bristol Beaufighter Crankshaft Position Sensor A Circuit Low Input
U284A Hyundai Galloper
U284A Mazda 626 Transmission Transfer Case Contact Plate 'D' Short Circuit To Ground
U284A Holden Ute Power Window RR Motor Circuit Failure
U284A Rover Montego Ignition Coil Primary Circuit Failure
U284A Lotus Super Traction Control of Engine Exceeds Time-Out
U284A Ferrari P5 Key Line Voltage