B0490 Diagnostic Trouble Code

B0490 is a kind of OBD-II Diagnostic B-Body 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 B0490 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
Reduction in engine performance, especially at low RPM levels

Possible Causes :

A faulty oxygen sensor. This will set a code in itself, however, a faulty oxygen sensor does not automatically condemn the sensor. The code just means that the sensor signal was not within specifications. An air leak or any of the above will cause an erroneous signal. There is a multitude of O2 codes relating to O2 performance which gives a clue to the problematic area.
Some aftermarket accessories and performance modifications
Defective ECU strategies or components will prevent proper regeneration

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. If the scan tool has that capability, and the scan tool can operate the IMRC valves, then the problem is either resolved and a simple code clearing is all that's left or a new PCM would be called for.

Process Tips

Diagnostic trouble code B0490 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 B0490.

Fortunately, B0490 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

B0490 Trouble Code For Specific Cars

B0490 Mbm Coupe Tourism A/C Post Heater Sensor Circuit Short To Ground
B0490 Holden Vq
B0490 Lincoln Continental Throttle Position Not Available
B0490 Gaz 11-73 O2 Sensor Circuit High Voltage (Bank 2 Sensor 3)
B0490 Audi 200 All Door Lock Input Short to Ground
B0490 Jaguar Xjs Seat Driver Occupied Input Circuit Short To Ground
B0490 Monteverdi Sierra Battery Saver Power Relay Circuit Failure