Hi Guys,

Sorry to only visit when I have a problem. Guess I can't think of anything to post otherwise! Ha!

I have an'03 Excusion. I took the rear bumper off to repaint it. In doing so, I unplugged all the backup sensors when I removed the bumper. I did not remove the sensors from the bumper when I repainted, just taped them off w/ masking tape. After reassembly, I discovered that the backup alarm system no longer works.

Symptons are: When I put it in reverse, the system "Off" light comes and will not allow me to toggle it back on until I put the tranny in nuetral, park, or some forward gear. There is no audible sound at all.

The system had been working prior to this. I suspect I either have a bad connection in one of the sensors or else I got some paint on the surface of one of the sensors. I tried wiggling all the connections and also cleaned all the sensors off w/ paint thinner but no success. There is also a relay in the fuse box for the backup alarm system. Do you know if there is any way to verify it's operation?

From reading previous posts, it appears that one bad sensor will disable the whole system.

The sensors are kind of difficult to remove from the bumper (That's why I never took them out prior to painting). I am thinking my cheapest route might be to buy a replacement sensor and start plugging it into each of the harness connectors and hope that the circuit will start to work when I find the problem sensor.

Any troubleshooting ideas or past experience with these systems would be greatly appreciated.

Thanks again for keeping up this forum. It's members are always first class.

 

Best of luck. I went down the same path with extra sensor and bumper wiring harness and it still doesn't work. I gave up and use mirrors.

 

The Reverse Sensing Module will set DTC's that can be read by a GOOD scan tool. If the OFF light is always illuminated there are codes set in this module. This should be your first step rather than guessing what's wrong. I know the OTC Genisys will access this module because this is the tool I own. Of course the Ford IDS will too. The OBDII units that Auto Zone has will not so don't waste you time there.

 

I have used the Actron Elite Pro Model 9185 and not picked up any back up sensor codes. Doesn't mean they aren't there, I just haven't found them.

 

This is not professional scan tool. Anything you can buy at Auto Zone is just for the DYI crowd. Your going to pay ~$1,000 or more the the good ones. Best to find someone who has one that you can use or even pay to have the codes scanned. MY Genisys does a complete module scan of the vehicle, with my 2001 EX it will read the PCM, TCM, GEM, ICM, RSM, ABS, SRS and probably a few more that I can't think of. With my 08 Mustang GT there are probably a half dozen more. It might me worth it to just bring it to the dealer have they diagnose the problem.

 

I have read on here that if the sensors are working they will emit a "tick, tick, tick" sound/vibration. I cheched mine by blocking my tires on a flat surface then turning on the key (no start) and putting it in reverse. Two were ticking and two were dead. That's as far as I got. If you put your ear to them, you can hear them.

If anyone knows the part number or where to get them that info would be appreciated. There doesn't seem to be much info in that regards on here.

Thanks.

 

eBay here:

FORD REVERSE BACKUP PARKING SENSOR 3F2Z 15K859 BA: eBay Motors (item 140382739476 end time Jun-11-10 10:18:24 PDT)

 

Thanks rlh68050,

When I had the bumper off, I started the vehicle and moved it with the sensor system unplugged. Do you think that could have sent a trouble code that permanently disabled the system?

 

It is possible. However I would think that after you reassembled everything the next key-up would have recognized that it was reconnected. If your trouble started after you removed the bumper and disconnected the sensors I would double check everything. If just one of those sensors is not working the entire system is disabled.

 

Thanks Rob,

I suspect it is a connector problem. The connectors are obviously designed to prevent moisture intrusion, but they are a pain in the *** to disconnect. I might have to take the bumper back off to see if I broke any of the pins when I unhooked the connectors.

Also, so far I have not figured out how to take the sensor out of the bumper. I thought maybe the rotated to a grooved slot before pulling out, but no luck getting them to rotate.

 

I replaced one of mine a year ago. I don't remember it being anything tricky to get them to release from the bumper. I believe that there are tabs that you have to move or something. I removed mine with the bumper in place.

Take a look at this eBay auction. There are some close up pics of the sensor. The tabs that you have to move stay on the bumper piece that holds the sensor. http://cgi.ebay.com/ebaymotors/Ford-...item3a52ea8bfc