Help diagnosing parking sensor problem...
 

I got into an accident where a car hit the driver side door. I took it to the body shop and when they completed the car I now have a parking sensor issue. They had to remove the front bumper when doing the repair. The problem is,

-When I start the car the front left and rear right sensor beep once.(always happens)
-When I push the parking sensor button the light flashes.(sometimes happens)
-When I put the car in reverse the parking sensor light flashes.(sometiems happens)
-When I put it into drive or park the sensor beeps once.(always happens)

I suspect something may have been damaged when they pulled the bumper off. I cleaned the sensors and it didn't help. The body shop doesn't know how to fix it. They pulled the front bumper to check things and cleared any codes but it doesn't work. Does anybody have any exp with possible causes for this problem? Any help would be great so I can help the clueless body shop.

Thanks,

bring it to the dealer, and bill the body shop

One (or more) of the sensors might be broken. Read error codes if you can to reveal which one is malfunctioning. Or switch PDC on and put your ear next to each sensor. There should be buzzing sound if sensor is ok. You can also try to touch it with finger to feel if there's slight a vibration (=working ok).

I had this problem, but it was because someone kicked it inside the bumper.
They only cost about 10$ to get replaced at BMW.:D

faulty X5 parking sensor
 

i had the same problem. the PDC light was flashing green instead of solid (normal). when turned on it let out a long beep.

i took it to BMW and they said the flashing means an error and to book it in, which in australia means $250 an hour to diagnose, then your mother, grandmother and children to fix...

i took the advice here and turned ignition on for electrics only, tuned PDC on, put my ear to each of the 8 sensors and heard a clicking noise, sounds like an ignitor on a gas stove.

only one of the rear ones had no clicking noise, so i pressed it and it started to click faintly and the PDC started to work again, it beeped, as my head was on top of the sensor!

so it seems to be a bad rear sensor, it's working again now, could be a bad connection, which i will figure out how to replace or fix (about $50 for a used one, about $350 from BMW australia)

thanks BMW for telling me that it was likely a blown sensor!

adding to my last reply, if you get under the rear bumper you can see the rear corner sensor and it can be reached by hand. i was able to push the plug in tight. the sensor seems to be fine now.

Hi there so are we saying that one faulty connection or sensor buggers the whole system?

If sensor is dead u can go around of a car and check it with the hand ! Used sensor will cost maximum 30$!
If pdc modul is dead it will be more expensive! Usually it lasts whole life time!

Sometimes one of the sensors do not want to work after car wach because of the water... when contact is dry it works again! Sometimes in strong winter...dirty, salt, snow... wash it good and drive again :)

No car wash bumped another car and one sensor is loose...and this is the one that is not making any clicking noise.....wondering if easy way to take out without having to remove all bumper? and if one sensor loose or damaged whole parking control system stops?

If one sensor is dead the whole system will not work! I have pre fl and I can take out sensors out from front bumper! As far as I know for fl cars u have to take off the front bumper! But I can be wrong! There is no problem about rear bumper! I had sensor pushed in in to the rear bumper and whole system was sounding in reverse! I took it out and no problem! I had problem only few times with my sensors as I mentioned...during winter or after washing! I walked around car checked sensor with hand and cleaned sensor with some cleaner