Thanks so much projectSHO89 for the schematics! I've been looking and asking for a week on the net for this info. I believe I should be able to use this to see if I have a short between the rear sensors and the parking aid module and also from the parking aid module and the parking aid disable switch. If the wiring checks out then I'm pretty sure the PAM will be bad. Ive already checked the parking aid disable switch and it was Ok.

Another question. Could you tell me where the parking aid module is located at?

I've only had this Expedetion for a month and this was one of the nonworking problems I was having. Again Thanks So Much!