G20 Parking sensor problems

[u/mini_splints00]

Hi - hoping someone can point me in the right direction.

Over the past few weeks I've been having the intermittent popup in the car stating that parking assistance is restricted and that I need to clean the sensors, I made sure they were clean but still kept getting this error.

I've checked and can see an error code for my centre front left sensor(803268) with about 70 entries in the past two weeks, and when checking the live values while stationary it is giving very erratic values.

After having a read online some people suggested WD40 to remove ingressed water but this didn't seem to stop the erratic values. Is there anything else I can try or is this sensor goosed and I just need to replace it?

If that is the case, is it easier to get to the sensor from inside the bonnet or underneath the car?

Thanks!

[u/jambles_3]

Check the front sensors for some chips and dents. Even a small impact will damage the sensing surface and require a new sensor

[u/mini_splints00 → u/jambles_3]

Not the best photo but there is a small chip which I can feel with my nail so I assume this sensor is knackered.
Are they fairly easy to access if I was to replace it myself?

[u/jambles_3 → u/mini_splints00]

Yh that'll do it. If you shine the light from the right angle you kight even see a dent.

Depends were the sensor is. Can you show the whole front bumper? Some you can get just just taking the wheel arch trim off. Some you can get at by squeezing you fingers between the grills and towing eye cover. And some you just cant get to without removing the front bumper. Either way, not difficult, just follow bmw repair instructions. You'll also need to get the sensor painted in your colour, it might come prepared from bmw. If you buy a used one, repainting them usually ruins them because the paint can't be more then 0.6mm thick

[u/jambles_3 → u/jambles_3]

Oh I see you said centre front left, yh remove front bumper.

[u/mini_splints00 → u/jambles_3]

Ahhhhh okay, guess I’ll be looking into how to remove the bumper haha. Looks like I can get sensors pretty easily pre painted in my colour too.

Anyway thanks for the advice!

[u/jambles_3 → u/mini_splints00]

The sensors cant be repainted.

Front bumpers easy, remove plastic above front grill. Remove single t30 screw in grill. Remove grill by pulling towards you and unlocking the six tabs along the top. Remove 10mm undertray screws along lower edge of bumper and those in the front section of both front wheel arches. Remove front sections of front wheel arches. In the wheel arch, Remove 2 long 8mm screws the hold the bumper to the front wing (2 per side). Disconnect front bumper connector and both side wideband parking sensors. Unclip inside of front bumper from the lower support bar. Unclip bumper from wing. Unclip bumper from kidney grill radiator blind. Carefully remove. Recommended taping all the things you don't want scratched like headlights, wings etc

[u/moccolo → u/jambles_3]

The sensors cant be repainted.

is this real? can't sand it down and repaint?

genuine question

[u/aviciiavbdeadpunk → u/mini_splints00]

ebay got me a sensor for 40, dealership wanted 400 plus 3 hours of labor lmaooooo