Reverse parking sensors

[Davids03Expy]

How's it going fellas, I have been searching but I can't find the right answer for my problem. I am having issues with my reverse parking sensors, my truck is a late model 2003 expedition with the 4 parking sensors and the issue I am having is that the reverse sensors sometimes gives me a message saying "check back up aid" or it beeps once and then automatically turns itself off not letting me turn It back on manually. My question is is

1. How do you check if a sensor is bad?
2. How to replace the bad sensors?
3. Replacing the back up module

Any help is greatly appreciative.

 

[Skauber]

I doubt the module is bad, probably sensors. They're exposed to the elements, so they are more likely to develop a fault. On mine it was a broken connector on one sensor. You can use a scan tool to check each sensor, or listen on each when someone enables the park aid, they should give a ticking sound when trying to check distance to objects. To remove a sensor, disconnect the connector on the back, then there's two tabs in the back you have to push out while pushing the sensor in to the bumper and remove it through the back.

 

[bcurbox]

so what was found?