boomie

Thanks in advance for your help.

I live in Canada and from what I read my BAS sensor is shot. But which one?

i have a 2013 BT. When I start my ML, both mirrors illuminate a red triangle. About 3-4 seconds later, the passenger side changes to an amber yellow while the driver side does not illuminate anything.

A few questions:
1) Can an someone tell me which sensor is shot?
2) Is there a difference between the driver side and passenger side sensor?
3) what’s the part number?

Again, thanks in advance.

excal

Not sure about left or right as I had different symptoms - one side was randomly flashing on and off even with no car on the side, and eventually would trigger the inop message until next restart.

But I found the best source is this eBay seller from Germany: https://www.m.ebay.ca/sch/i.html?sid...ne=true&_pgn=1

Came out to about $300 CAD shipped and yes it's the same part for both sides. There are a whole bunch of part numbers for different model years so best to send the seller your VIN and he will match it to the correct listing.

Installation wise, I jacked up the rear differential and placed jack stands on both rear jacking points, removed the wheel and wheel well cover, then reached in behind the bumper to remove.

Babukb2

are you sure the sensor is bad?
i ask because i got the same error last summer and it turned out to be a dirty sensor. i went around the car feeling around with my hand behind the bumpers and also banging my hand on the bumpers, and lots of mud/dirt fell out. after that the sensor worked fine for quite some time.

also to determine which sensor, you may be able to find out with an OBD device. i am also getting this same error now, and when i ran an obd scan it told me that it was the right rear sensor causing the error. odd thing this time is that cleaning the sensor did not fix the problem, but the problem seems intermittent. it will say inoperative, but once i start driving it starts to work fine. then usually from leaving the car parked for some time again i get the inoperative error when starting the car, but then it works fine once i start driving.

im also having one keyless go door handle act up and sometimes work and sometimes not, im wondering if the 2 issues are connected and if im maybe not having sensor problems but a battery problem.

excal

You may want to pull the connector and check for signs of corrosion. Mine looked fine but others pointed to water intrusion through the connector as the cause of the failure. These sensors are located in an area that gets significant water, salt spray and dirt kicked up by the rear tires so it's no surprise to see these fail. When I installed the new module I filled the connector with dielectric grease - hopefully this will keep the water out.

Babukb2

I pulled the radar sensor this past weekend. i did see some red residue on the outside of the sensor, nothing to be concerned about since it was on the plastic case and outside. i unplugged the connector and cleaned it out as best as i could and also sprayed an electric parts cleaner in there to clean out any gunk. i did see a little bit of what looked like a thin red paste almost, or maybe just red/rust residue on the inside of the plastic connector from something leaking in (my assumption).

cleaned it all out and put everything back but the error still pops up. again odd thing is i get the inoperative error, but in about 1 minute or so the error disappears, blind spot and all sensors seem to work fine.

any other thoughts on what it could be/what i could check? maybe i didnt clean the sensor connector well enough?

BTW what a PITA to get to that sensor behind the bumper, my arm is wrecked from trying to squeeze in there and get the sensor out.

excal

It could just be the electronics failing. I didn't see any sign of water intrusion either but it was definitely working intermittently. I even swapped left and right sides to rule out wiring and the problem moved to the other side.


Did you remove the rear wheel and wheel arch liner? I tried squeezing between the bumper and heat shield at first and it proved impossible. Reaching back from the wheel area was easier but still tricky getting the connector to release as you can really only get one hand back there.

Babukb2

i squeezed between the bumper and whatever else was there, it was very tight (this was on the passenger side). i believe the heat shield is on the driver side and that is the side i wasnt sure how to get at. maybe wheel well is an option, i think i also saw a video/post about loosening a bolt from the heat shield and bending the heat shield back far enough to get a hand in there and reach the sensor.

crazy1eye

You know here in Canada those sensors are covered by MB under an extended warranty program. I had them changed on my ‘12 E63 over a year ago & just recently on my wife’s ‘12 ML350, call them.

just to be clear, neither of my vehicles had/have an extended warranty, nor were they still on the factory warranty

Potrice

Are you serious!? If so, do you have any documentation/proof for this program? In case mine crap out (and they will at one point with our winters) I can have something to back me up. Thanks in advance.

crazy1eye

Not much there except you see it’s marked no charge

boomie

How do you know it’s covered vs an exception was made?

My issue turned out to be a faulty mirror. I didn’t even know the mirror had anything to do with the BSA.

keptbenz

Hello I see this post from years ago. Did dielectric grease help? I'm on my 4th set of Blind Spot Detectors. I'm looking for advice on protecting them from the elements

excal

I haven't had any more failures since then, and I did fill both connectors with dielectric grease.

keptbenz

Thank you very much. I will try it.