So I know the rear park aid topic comes up often and there is a DIY in it. Counting from left to right, I know there is some malfunction with my 3rd sensor. When it's not working I get the typical 3sec beep upon reversing first time each starup. Weird thing is that in some extreme cold, or driving in snow or rain, or getting a carwash with underbody wash, the sensors work fine. I believe there is some connection problem if getting it wet it making it work (since water is an electricity conductor and probably is completing the circuit).

That's not my main concern though. I took a two hour drive this weekend through freezing rain, rain, snow, and slush (yes all in one single trip LOL). When I reached my destination, I noticed whenever I put it in reverse the beep is now one long continuous tone and is on for as long as the car is in reverse (no more 3sec thing). The 3sec malfunction beep only happens the first time the car is put in reverse after a startup; this is now EVERY TIME it's in reverse. It's as if there is some obstruction taped directly on top of one of the sensors giving me the continuous warning.

But I cleaned the dirt and snow off the sensors and it's still happening. Even after it's been sitting and everything should have been dry, it still does it.

Any ideas?

 

AML, put your ear up to each of the rear sensors and see which one is clicking and which one isn't. I bet you will find that one of your sensors will not be clicking or it will be clicking really quietly. That is your bad sensor and it needs to be replaced. Just a warning though, the center sensors are different than the outer sensors. SO, make sure you get the correct sensor.

 

Thanks, I did the test before and that's how I determined the 3rd sensor was faulty. If it's still giving the long continuous beep I should go out and check again. But I'm wondering what would cause it to give me the long beep every time instead of the 3sec one.

 

AML, it may be possible that due to not repairing the initial problem, it has caused other issues. Not sure what to tell you other than to replace the bad sensor and then see what you have at that point.

 

Sorry to be so pedantic, but water is not a conductor of electricity! its the foreign matter (dirt etc) that conducts the electricity.

 

phil, you are correct but incorrect at the same time. You are correct in that normally it is what is dissolved in the water that causes it to conduct (as water is a very good insulator). The flip side is that with the back up sensors, having water inside the sensor can obscure the sound wave that it makes to detect when something is behind the car, leading to it giving a false indication that something is there because the water reflects the sound. So, in something like this, water can and cannot cause issues. All in how and where it is.