One problem related to wiring has been reported for the 2002 BMW X5. The most recently reported issues are listed below.
I own a 2002 BMW X5 with less than 37,000 miles. In the last 6-8 months I have had to replace the control arm. More recently, I had to have the engine harness rewired and the throttle body replaced. My brake light is constantly going out even though I have replaced bulbs and sockets numerous times. I have spoken to other X5 drivers who have had some of the same problems so I'm beginning to wonder if it's a bigger problem than just my vehicle.