Parking sensors no longer work

[resq302]

Just had an instance in my 2012 Ram 1500 where the back up  / parking assist sensors stopped working.  As soon as I put the truck into reverse, the parking assist off button comes on without touching it making the system inoperable.  Pushing the button makes no change.  If you have the truck in drive, the button functions properly.  I disconnected the harness for the back up sensors by the rear bumper to see if it still had the problem and it did so I assume the problem is not with the sensors themselves.  Is there any other place to look?  I have an extended warranty but if the repair will cost me less than $100, I'd rather fix it myself.  Otherwise I can bring it back to the dealer and be without a vehicle for a day or so.  Any opinions or suggestions?

Thanks,

Brian

[ACUDANUT]

Can't help you, but won't the dealership give you a free loaner car ?

[John_Kunkel]

Have you gone into the Personal Settings mode and checked to be sure nothing has changed?

[resq302]

Dealership claims they don't have enough loaner cars and will not give out a loaner car unless it is a "major" problem such as engine failure or trans or etc.  Technically, I can get reimbursed through Chrysler after a day of being without a car and geting a loaner car however, I have to pay up front and "HOPE" they say it is qualified for a reimbursement.  I've heard of friends getting burned before with Chrysler not wanting to pay out on claims.

John, I have not changed anything setting wise probably in the last couple of months.  As it was, the last trip out with the truck today had the message come up for a split second saying "Service Park Assist System" and then the message disappeared.

[odcics2]

If your insurance coverage has 'loaner' specified, or you have the warranty with a loaner specified, there would be no problem.
Now, if you have no loaner coverage, yes, they won't pay.   

[ACUDANUT]

I am Sure Chrysler has the low ball 3 years 36,000 miles bumper to bumper. They have to give you a loaner car.   Make them honor it and loaner car.

[draftingmonkey]

Dealership claims they don't have enough loaner cars ....

Tell them you have no problem test driving a 2015 Ram off the lot while yours in in the shop  .

[bakerhillpins]

I am a bit confused why you might believe the disconnecting the sensors would make the problem CLEAR if the sensors were bad??  I would expect that disconnecting the sensors would make the problem occur. You could test this by disconnecting the front sensors and seeing if you have an issue.  With my 2014 RAM any individual sensor being covered with crap will cause the system to shut it down. It's reported via the dashboard monitor as sensors have crap on them, wipe clean to fix.. or some other such nonsense. Do you see any information message when you first start the truck and put it into reverse?

[resq302]

Bryan,

I figured if the problem was with the sensors, if I unplugged the harness before the sensors, it would make it so the switch would stay on when I put it in reverse.  It almost seemed as if there was a direct short which made the switch turn "off" and have the light come on in the switch indicating the system was turned off.  Funny thing is, this only happened after I got the truck washed at the car wash and had the under carriage washed too.  Once the truck dried off (started working yesterday and took about a week to start working normal again) the parking assist system started functioning like it should. 

Also, I only have the rear parking sensors and not the front ones.  My Dad's new 2014 Ram 1500 sport has the front parking sensors as well as the rear parking sensors.

What is weird is after the system stopped working, two days later it had a message show up to Service Park Assist System but it only appeared once and never came back.  No codes or messages were in the truck either with my scan tool.  The only time this happened is if the truck was in reverse.  If I was in drive or neutral, I could hit the switch to turn the park assist system off and the light would light up like it should.  What was happening was if I put it in reverse, the "off" light would illuminate shortly after putting the truck into reverse.  Again, now that the undercarriage has had a good chance to dry out, the problem went away.  The only thing I can think is that there is a wire that has chaffed and is causing a short to make it think the switch is turned off, or a plug is not completely pushed together, just like the harness was for the pass side headlight assembly, when I picked up the "Certified Pre-owned".

[bakerhillpins]

My understanding is that the only time the system reads/tests/uses the rear sensors is when it's in reverse and that unplugging the sensors at any point when the system expects them would cause the switch light to come on indicating the system is off.

Ah the under wash is significant. I would grab a hose now that it works and start hosing down individual sensors and connectors until it stops working. A individual chaffed wire on its own wouldn't be an issue, it would have to short to something like the chassis or another wire.

[resq302]

Yeh, I agree.  What is weird is that when I am in drive or anything but reverse, the button works fine and you can turn it on and off as normal.  Yet, once it was in reverse, (and it was still wet) the switch basically was inoperative and was constantly on the "off" position.

[bakerhillpins]

Yea, on the 14, once it marks it bad the light is permanently on indicating that the system is disabled. Happened several times so far this winter with all the rain and freezing we have had up here.

[resq302]

and yet I've only had the message pop up once about having it serviced and since then nothing!  no codes even stored   

[bakerhillpins]

That doesn't surprise me at all. If they setup the software to start logging codes on these systems they would be overrun with "code clears" at dealerships for situations where water/crap got all over the sensors and drivers didn't take the time to clean away the debris. Think of how often in the winter you get a layer of ice on your vehicle that hangs out for a few days. Happens to me up here quite a bit.

[resq302]

Even with my Ford, I've had a layer of dust / dirt on the sensors and they worked fine.  My Ram still gets that dust / dirt on it and I've had no issues.  Even with the rain water or water getting drawn into the tailgate area from driving from the vacuum they still worked fine.  I dunno, just baffles me thats all.  Looks like I won't be able to take care of this truck with trying to get the salt off the undercarriage in the winter.  lol.

[bakerhillpins]

You are correct, just water on the sensors isn't enough to shut them down. That's lazy typing on my part and the only times it has shut down for me is from ice buildup and mud (as a result of rain and living on a dirt road of course  ). 

I still say that you have a bad connector and need to spend a few minutes spraying water on each connector with a hose and then testing the system. At which point you can fix it and start washing the under body again.

I personally undercoated my RAM with Fluid Film rather than constantly dealing with hosing the under carrage.

[resq302]

You are correct, just water on the sensors isn't enough to shut them down. That's lazy typing on my part and the only times it has shut down for me is from ice buildup and mud (as a result of rain and living on a dirt road of course  ). 

I still say that you have a bad connector and need to spend a few minutes spraying water on each connector with a hose and then testing the system. At which point you can fix it and start washing the under body again.

I personally undercoated my RAM with Fluid Film rather than constantly dealing with hosing the under carrage.

  Its all good!  lol   What I did the last time when I disconnected the harness at the frame was chock the wheel, put the parking brake on and put it in reverse and just left the ignition in the on position without the engine running to try and test it.  I'll do that again with a hose or spray bottle with water on the connections.  Nothing like water issue or an electrical gremlin only to have a combination of the two make it worse!

[bakerhillpins]

    Yes, all good. Followup was for clarification so that someone didn't actually think that the system was shutting down due to just water on the sensor.

Be sure to let us know if you do find the problem. 

[resq302]

will do!