Reverse sensors

[fordfan2006]

My brothers 03 Explorer XLT 4.0 has the backup sensors and they no longer work. how do i find which one is bad?

 

[JoshMcMadMac]

The most direct method would be to use a scan tool, like a $10 ELM327 module from eBay or Amazon, along with FORScan on a computer. That can pinpoint which sensor, or if it is the module itself. Otherwise you can try listening for each sensor to click when reverse is engaged; if one does not click like the others, it is bad.

 

[Number4]

^^^ listening for the clicking is the cheapest method. Just don't get run over or inhale too much exhaust. Either one of those happen and the ELM327 would have been cheaper.