One problem related to brake sensor has been reported for the 2002 BMW X5. The most recently reported issues are listed below.
Window bust out for no reason, coolant container light on, brake lining, windshield wiper motor quit without notice. . Motor hot and froze up, lights on dash coming on and off. Sensor had to be replaced. These things happened without notice. Wheels that have to be aligned and still tires have to be replaced often.