My reverse sensors on my 2005 SD have worked flawlessly until this past week.

My wife dropped it off at the dealer for a routine oil change...they told her it needed the 100K service and she told them to go ahead. So, they did an oil change, coolant flush, diff fluid change, brake fluid change and changed the fuel filters.

That was OK except when I picked up the truck & put it in reverse, the RSS light on the dash button immediately lit up (OFF). I tried to turn it back on...yet, each time I put it into reverse it turns off. It won't work at all.

It's frustrating...it did not do this when I took it in.

Suggestions on what I should check before I take it back to the dealer?

Thanks,

Rick

 

If any of the system components are not working correctly, the system defaults to "OFF". Usually a single sensor is at fault. When "R" is selected you can here the sensor make a tiny click, and if one is quiet, it's typically the problem.

Seeing this issue seems to have started while at the dealership, I'd take it to them and explain the situation. They can identify the problem component in no time with IDS.

 

Check all your connectors at the sensors on the bumper and going back towards the cab, might be on knocked loose..

 

it could be a fluke, if there is any corrosion on the face of the sensor they are done, I just bought 4 from Ebay

 

Put the parking brake on, turn key on, put in reverse and go to the rear bumper and listen to all 4 sensors, the one that is not clicking is your problem! this assumes that the dealership did nothing to cause damage to the RSS.

 

Oldred that's a good tip there

 

Good test...I did that and none of them click.

Groan..off to the dealer.

 

Check the backup system warning speaker. It will also fault the system. I spent $500 for new control module, 4 sensors and dash switch until I read on this site that the speaker could be the problem. I felt like an idiot and poorer after I read that. I pride myself on my troubleshooting skills but that was a humbling experience. The speaker is easy to check and cost about $25 to replace.

DSMMH

 

This site is what helped me fix my sensor's too, thank God for FTE & Ebay

 

My sensors work fine. When it sounds expensive, STOP! But seriously they seem to fail alot. My friendhas an f 350 and I can never recall them workin.

 

Had similiar problem... Since they changed the Diff fluid the tech may have hung his drop light on the harnes that plugs into the rear sensors... I went through the same problem dealer replaced all sensors and no fix.. they decided to order the module.. Went home crawled underneath and found that a circular shaped plug on the main rear harness wasn't fully seated ...separated and plugged back in problem solved... Also each sensor has its own weather pack connector(they should call it not so weather tight)... look behind the bumper make sure they are seated properly... One bad connection and the system will shut itself off... Also car washes seem to bring out gremlins in the park assist...

 

So what is the test for the speaker?

 

I have replaced two sensors over the last 5 years (truck is 7+ years old).

First, wash each sensor with a hose or pressure washer at the car wash. A dirty sensor or dirt in and around the sensor and the housing can cause issues.

Second, check connections behind each sensor in case one came loose or as an earlier poster stated, the mechanic put his light up there???

Personally, I would just go to the dealer after cleaning off each sensor, and if it stil does it, have them look at it and use the "reason".... it was not happening when I brought it in and I am sure you would have told me about it if it was (like you did about the 100,000 mile service).

Sensors go bad and there is no ryme or reason for them. Cold weather and snow and road salt has an influence on them (in a bad way that is).

Check the basics and just go back to dealer and hopefully a nice personality and the fact that you just spent how much money last week... will probably get you a free inspection at least.... see if you can watch and learn which sensor it is... then maybe depending on what they quote you, you can fix it yourself. There are different sensors for the different positions on your bumper.

Good luck,

 

The 4 sensors are all the same part# on the truck, but there is at least 2 different part # they could be, the # is on the sensor but you have to pull it out to read it.

 

Interesting... on my Excursion, I remember (or I thought I did) that the outside corner sensors were different part numbers than the sensors in the middle of the bumper?

When I had a bad sensor, they hooked up the computer to the OBDII port and it told them which one was bad. The mechanic switched the two outside sensors... and upon re-testing, it showed the "other one was bad"... which then told us that it was the sensor and not something else (as the computer showed that the problem moved... since we "switched sensors around".