I have an '05 XLT with park assist (backup) sensors. The "off' indicator lamp on the console P button stays on all the time and the option doesn't function. Is this an indication that one or more sensors maybe defective or just wet? Is there a method to test a sensor other than listening for clicking when the truck is in reverse? The connector has three leads which according to a few schematics I have seen are common battery & ground and individual inputs (RO,RI.LO.LI) to the Parking Aid Module. Checking for battery and ground is easy however does anyone know what to look for on the module input leads? Lastly does anyone know where the Park Assist Module is located in the truck?

 

Likely a sensor, or sensors, are bad. Mine did the same thing, and luckily my buddy works at the OEM and got me 4 new ones for free.

My suggestion would be to buy one sensor, and systematically replace each of the 4 with it until you can get the OFF light to turn off. If that doesnt work, it might be two or more sensors that went bad, and you might as well just replace all 4.

 

Here is what I did. I had the same problem.
Turn your truck to on but don't start it. Put it in reverse and set the parking brake. Go put your ear by each of the sensors, very close to them, and the functional ones will make a ticking noise.
For the ones that don't function, check the wires first. Each sensor has 3 wires. A power, ground and a sensor. If you have a test light or something check the wires. If you have power and ground, it's the sensor.

If you are missing power like I was, follow the wires back, checking with a test light occasionally, mine was pinched on one of the bumper mounts and had split the wire, quick splice and I was back in business.

 

Thanks for the input. I will probably try the low tech method of listening for a clicking first. I'm not fond of purchasing parts when I'm not certain if it will correct the issue. I would still like to know where the module is mounted in the truck. Any ideas?

 

If I remember correctly the module is underneath the truck near the spare tire. I also have a sensor I would sell you cheap I'd you need one!

 

no...your thinking fpdm

 

Listened to determine if the sensors made any noise with the ignition ON and the transmission in reverse. No noise from any of the sensors. I pulled one connector and checked for battery and ground across two of the pins which showed about -10.5 VDC. Probably a little low since the truck wasn't running. Looks like I need to find four sensors and replace them one at a time to see if it will fix the issue.

 

Not sure if you have this yet or if it's useful but just in case

 

I have an 05 f150 xlt. Every problem I have had with my truck I have found the answer to fix it in these forums. I love this website and thanks to all the input you guys are posting. Friendliest On Repair Day..... haha

 

The PAM is up above the parking brake. Little black box with two sets of wires and the backup speaker mounted to it.

Let's see if I can post this photos: https://www.f150forum.com/attachment...o-photo-3-.jpg