backup sensors

[dallert]

The backup sensors on my 2002 Mountaineer are not working. The switch inside changes to Off everytime it is turned on and the vehicle is put in reverse.
How do I troubleshoot what the problem is?

Thanks,
Dave

[shorod]

First question is have they ever worked in the time you've owned the truck? The reason I ask is the rear parking aid typically defaults to "On" and will automatically come on when you shift to reverse. If you are pressing the switch to turn them "On" you may in fact be turning them off. You might want to check your owner's manual to make sure you have them enabled and are using it correctly.

The easiest way to troubleshoot what's happening with the backup sensor system will be connect a professional scan tool to the truck and check the backup system. Since the system is apparently shutting itself off it likely has detected an issue and triggered a diagnostic code.

You should also confirm that your backup lights are in fact coming on and it's not just due to an issue with how the shift lever is adjusted. Another item to check would be the fuse for the "Parking Aid Module" which according to the service manual should be fuse F2.27 (7.5A) in the Central Junction Box.

-Rod