If I have one out of the four sensors bad would that cause the whole back up system to not work?

 

yes

Listen to them all when in reverse and close enough to something for them to activate.

The one(s) not clicking is the bad one.

 

If one is not working, the whole system doesn't function. To diagnose this, you'll need to scan it for codes.

 

Thanks for the clarification Mike, I had been taught to check for the clicking sound. Did this change from the 7.3L to the 6.0L? They all still get power don't they - even with one not working (ie they aren't wired in series are they)?

So you are saying that you will get a specific code for an individual sensor?

One other way is to buy one sensor and replace them one-at-a-time and hope you only had one bad one. They are not cheap.

Part # YL1Z15K859AA ($100 each)

 

There are numerous threads such as the ones below talking about it w/ the 6.0L (the clarification being that you don't need to be next to something, just having it in reverse w/ emergency brake on is enough to get them to make a slight sound according to the threads). The alarm system does in fact quit working, but it is stated in the threads below that the individual sensors will still try to operate:

backup sensor - Ford Powerstroke Diesel Forum

http://www.powerstroke.org/forum/6-0...-went-out.html

 

I've never heard of them making a clicking sound like you describe to be honest with you Mark. I've always diagnosed them using a scan tool and scanning the PAM (Park Aid Module) for codes. And yes, one of them failing will set a code for that specific sensor. There are three wires to each sensor. Two of the three are on the same circuit on all four sensors. Only one of each is specific to the position of each. I have also found that more often than not, the main park aid harness is the bumper has "green-deathed" on one or more circuits. Believe it or not, the price of the harness is actually cheaper than the cost of one sensor, making it not too worthwhile digging too deap into trying the pinpoint the source of the issue in the wiring.

 

Put a hose to my sensors this AM and you can definitely hear a faint (rapid) clicking sound from them, so I suspect that you can still use the process to identify one bad sensor.

That being said, the corrosion on the harness being the main culprit is good to know. I definitley can believe that! Not long ago, my wife backed the truck into a pole and the backup sensors quit working. The shop overlooked this problem while fixing the bumper/tailgate/etc., I took it back quickly to get it covered by the insurance, so I didn't really troubleshoot it. I would have bet money that it was a sensor, but it turned out to be a corroded harness. We do not have issues with ice here so it has never been exposed to salt. I never take it to the beach either. If the harness will corrode in our "favorable" climate, I can imagine what it would do in other locations.

Lastly (so I don't break my typical mode), do you have a part number for the harness Mike? Because I took the truck back for an additional repair (charges went to the insurance), I didn't get a part number for the harness from the shop receipts.

 

I know when I changed my rear bumper to the '11 one,, I was gonna drill holes to add my sensors,, and there are cutouts in different positions for each hole. So the far right sensor,, will not go in any other hole. Prob a useless observation. Lol

 

1C3Z-15K868-AA (I think???)
I'm not 100% sure on the prefix and suffix of that part number, but I am 100% sure on the base number portion so you might want to verify that for your own benefit.

 

The part number for the sensors on these trucks is 3F2Z-15K859-BA for your reference.

 

So all 4 sensors are the same number?? Does the sensor install in a housing,, and that housing snaps into the bumper?

 

Yes, and yes. And yes a 2011 and newer truck uses the same part number for the sensor.

 

mine is an 04 f250, are they all the same and is the dealer the only place to get them?

 

Not sure if they are available at the parts stores

 

I had my bachup system go bad. Cost me a lot of $ to fix it by guessing. Had yellow fault light on dash switch. I bought the module $300, 4 sensors @ $50 each and the dash swithch @ $34 replacing them one at a time. No joy! The speaker was bad. I believe it was $20. Replaced it and all of the original parts (module and sensors) are good.

Ed