Until about 2004, these things are all suspect, and cause those symptoms, but eventually can stop the car from running period. My friend the ex-tech said they did a lot of those under warranty on 2004> x5s but by 2004 they had this problem under control. I encountered this when my ICV crapped out.

You could probably replace that yourself over a weekend. Realistically an afternoon. I have disconnected nearly all of those connections myself for other issues, and I absolutely hate wiring, but the design of the harness itself is pretty simple.

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2001 E53 3.0 5pd