I don't know if this is the same solution...

During cold starts with a failing battery, I would get the CEL almost every morning. I had to drive the vehicle at least 20 miles, park it let it sit and then restart it twice more with waiting periods in-between before all the sensors reset.

I cannot say how long the waiting periods were because I just let it sit while I was at work. So for me it was...

1. Get CEL.
2. Drive 35 miles to work.
3. Start vehicle at lunch time - go to lunch. Stop Engine.
4. After lunch (about 45 minutes), start car, CEL is gone.

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2006 X5 Sport 4.4i