U240A Diagnostic Trouble Code

U240A 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 U240A diagnostic trouble code may include:

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
Faulty or damaged wiring
Hesitation upon acceleration
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.

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.
Defective ECU strategies or components will prevent proper regeneration

Repair Processes :

It should be pretty close to battery voltage (12 volts). If not, then this is the circuit that has the problem. 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. Oxygen sensors signal the engine management computer the amount of oxygen present in the exhaust, which is used in determining and controlling the fuel ratio.

Process Tips

Diagnostic trouble code U240A 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 U240A.

Fortunately, U240A is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U240A Trouble Code For Specific Cars

U240A Fiat 35 Hp Lamp Air Bag Warning Indicator Circuit Failure
U240A Cadillac 314 Damper LR Circuit Short To Battery
U240A Abarth 124 Spider 1-4 Upshift (Skip Shift) Solenoid Control Circuit Malfunction
U240A Alvis Tc Air Suspension Compressor Relay Circuit Short To Battery
U240A Mazda Mazda 2 Ii Turbo/Super Charger Boost Control Solenoid Circuit High
U240A Alfa Romeo 8c Accelerometer Rear Circuit Failure
U240A Sbarro Ionos Injection Pump Fuel Metering Control "A" High (Cam/Rotor/Injector)