EmissionsSeverity Medium: diagnose soon

P0490Exhaust Gas Recirculation "A" Control Circuit High

What it means

The EGR control circuit reads too high a voltage, usually an open circuit or a short to voltage.

Symptoms

Rough idle or stalling
Loss of power, sometimes limp mode
Black smoke (diesel) or pinging under load (petrol)

Common causes

Open actuator winding or control wire
Control wire shorted to voltage
ECU driver fault

What to check first

Measure the actuator resistance
Check the control wire continuity
Run the actuator test

Can I drive with P0490? Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.

Generic OBD-II meaning. Manufacturer-specific meanings and checks can differ; always check the service information for the car.

Cases with P0490 (0)

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P0490: questions and answers

What does P0490 mean?

P0490: Exhaust Gas Recirculation "A" Control Circuit High. The EGR control circuit reads too high a voltage, usually an open circuit or a short to voltage.

What are the symptoms of P0490?

Rough idle or stalling. Loss of power, sometimes limp mode. Black smoke (diesel) or pinging under load (petrol).

What causes P0490?

Open actuator winding or control wire. Control wire shorted to voltage. ECU driver fault.

How do you diagnose P0490?

1. Measure the actuator resistance 2. Check the control wire continuity 3. Run the actuator test

Can I drive with P0490?

Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.