Blind Spot Assist Inoperative - Journey to fixing it
Member
Joined: Dec 2013
Posts: 219
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From: Bluffdale
2017 AMG C 43 (W205); 2019 E 300 (W213); 2008 ML 320 CDI (W164)
Most of this thread is old - hope someone will respond! I know what the front radar module looks like and where to find it. It's easy to see the locations of the Parking Sensors on the front and rear bumpers. Are the Parking Sensors also used for the Blind Spot assist, or are the Blind Spot Sensors separate from the Parking Sensors, but also on the bumpers and hidden from view from the outside? I anticipate the Blind Spot Sensors are separate from the Parking Sensors.
MBWorld Fanatic!
Joined: Jan 2016
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From: In the Shadow of the Tetons
2013 ML350 Bluetec
The blind spot sensors are hidden beneath the bumper skin. They're about the size of a deck of cards and are located at roughly the corners of the rear bumper, about halfway up the bumper from the ground. On my bluetec each one can be fairly easily accessed by removing some bits from the bottom (muffler heat shield on one side, DEF tank splash guard on the other iirc). Same part number on each side, wire harness enters the sensor block from the end closest to the back of the car.
MBWorld Fanatic!
Joined: Jan 2016
Posts: 2,749
Likes: 881
From: In the Shadow of the Tetons
2013 ML350 Bluetec
I replaced both rear blind spot sensors on my ML last week and have yet to see the "blind spot inoperative" message since. It popped up every few days previous to that, so I'm going to tentatively declare that a win.
Paid about $92 per sensor all in via WalMart.com, and they came with a 3 year warranty. Time will tell if they're worth it.
Paid about $92 per sensor all in via WalMart.com, and they came with a 3 year warranty. Time will tell if they're worth it.
Last edited by rapidoxidation; Sep 15, 2024 at 10:52 PM.
Senior Member
Joined: Nov 2015
Posts: 272
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From: Ottawa, Ontario
2013 ML350 Bluetec, 1966 Ford Mustang Convertible (sold)
What Rapidoxidation mentioned is solid information and 100% correct. I also recommend you add silicone around the sensor. My previous defective one cracked and water got inside. That's how they go bad. I added silicone along the middle line of the sensor. I also plugged the wiring in the sensor and added a bunch of silicone in there to prevent any water or moisture from coming in. I really believe that the sensors will work forever by sealing them shut with silicone. Once you change one, you don't ever want to mess with them again. It's not a big job, but it's still annoying if they stop intermittently stop working and you constantly have to mess with them. Do it right, do it once. My 2 cents.
MBWorld Fanatic!
Joined: Jan 2016
Posts: 2,749
Likes: 881
From: In the Shadow of the Tetons
2013 ML350 Bluetec
A few hundred miles later:
No "blind spot inoperative" message, and I've driven through a few hours of driving rain with zero issues. Water was almost invariably a trigger for the message, with the worst case scenario being the blinkers would no longer work. Haven't had any problems since the replacement with WalMart sensors that looked exactly like virtually every sensor offered except the MB ones, at any price. When I say "exactly like" I mean right down to the numbers printed/embossed on the sensor case. Any bets that every blind spot sensor in existence in Mercedes World is made in one factory?
No "blind spot inoperative" message, and I've driven through a few hours of driving rain with zero issues. Water was almost invariably a trigger for the message, with the worst case scenario being the blinkers would no longer work. Haven't had any problems since the replacement with WalMart sensors that looked exactly like virtually every sensor offered except the MB ones, at any price. When I say "exactly like" I mean right down to the numbers printed/embossed on the sensor case. Any bets that every blind spot sensor in existence in Mercedes World is made in one factory?
