I just took mine in today for the same thing.

4 weeks ago the wife called while I was traveling and said the DSC, abs and brake lights came on. It was then parked. When I checked it out 2 weeks ago the 3 lights came on with the start up of the car and stayed on. tried several times and got the same result.

This morning when I started the X5 up to take it in, the 'service vehicle soon' light came on and the other 3 were off, but the engine was running rough.

Drove 35 miles to a recommended service center with only the 'service soon' light on.

Fault code check indicated the Steering Angle Sensor. Cost for a sensor $287, install 3hrs or $315. I didn't get it done since the lights had been out. They said they would need to disassemble the entire steering column to change the sensor. I wonder if these can reset themself from sitting 3 weeks?

Had more than one issue. Oil leak from the valve cover soaked 3 plugs with oil causing the engine to run rough. They changed the gasket, cleaned the plugs and coils and it runs like a champ. Don't know if the 2 issues are related, but thought I would post it up as reference info.

Drove home and all lights off.

If the ABS/DSC lights come on again, i'll have it done.

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2003 X5 Steel Grey
3.0i e53