Parking sensors stop working intermittently W212

[kilters]

Hi All,

Hope someone can point me in the right direction. Have a strange issue where my parking sensors both front and rear stop working for about two cycles of turning the car on and off. Third time they start working.

I can't seem to figure out what causes them to not activate in the first place it but may possibly be due to the fact that where I park at night it is very close to a wall and when they start up the trip out. Another thing I need to test more is if I turn off the ECO setting on the dash. Button is right next to turning the sensors off so wonder is there some cross communication.

I've a 2013 W212 E220 CDI SE facelift model, had it about 2 weeks. Only issue I've found on it.

Any ideas?

 

[Diesel Benz]

Can you describe what happens when your sensors stop working? Do you get the red leds (only red) on for each corner or is it that you do not get any proximity indication about objects close to the car etc?

 

[kilters]

Hi,

Thanks for the reply. The front and rear strips are completely dark. When I am driving slowly, normally the 2 LED's in the middle would light up to show the sensors are active but when the issue occurs they are completely blank. Same with the rear sensors when I put it in reverse.

Pressing the Parktronic on/off button doesn't reset them either. They just seem to come back working after a few starts.

On another note, turning ECO on and off seems to have nothing to do with the issue after a few tests.

Very strange. I still have warranty with Mercedes so may just get them to take a look once I confirm I'm not doing anything stupid

 

[Diesel Benz]

OK, it is not a typical sensor fault then (would fire red leds on both sides).

Sounds like a control unit issue or a wiring issue or a bad contact at t, killing the whole thing.

 

[kilters]

Just wanted to close this one out as I think I've discovered the root cause of the issue.

Simply put, if I turn the key in the ignition too quickly while starting, the sensors don't initialise properly. Works if I turn the key to position 2, wait for the parking sensors to light up, signifying the self check, then start the car once the lights have gone out.

Should have caught this sooner really but never saw it mentioned in the manual.

 

[Diesel Benz]

Good to know you have found a way to control the Parktronic behaviour but there should not be any need to wait for the Parktronic system to initialise before starting the car. Something must be wrong, hopefully someone from the forum has an idea about the issue (even if you would not consider it worth pursuing further).