On my wife's 2012 ML350, we are getting the Blind Spot Inoperative message. So initially I looked under the car and saw the drivers side connector had a broken wire flush with the connector so it was hard to fix. I ended up getting a new connector online and soldered the wires in, easy job. Seems to have worked for few hours and then it got wet out and now I am seeing the error again. I am sure the new connector is fine and thinking maybe another issue but was curious if there was a way I can eliminate the possibilities. I'd rather not have to make a trip to the dealer for them to scan the car. Would a regular OBD scanner pull what side the issue is present at? I don't want to go replacing the sensors on both sides and dumping cash down the drain. I have not yet looked at the right side to see if that connector is also trashed.

 

hi, since you are confident you repaired the connector/wire on the left side, check the connector and corresponding wires on the right side.

 

For less than the price of a dealer visit you can own a bidirectional scanner like icarsoft mb2 or such. Something every MB owner should have in their tool box, IMHO.
Cuz you KNOW somebody is going to ask: What Codes? If you don't know the answer, anything you d is a guess. So is anything anyone advises.

 

There is a radar module in the rear bumper (passenger side) that gets wet/corroded and causes this error as well. If you bang lightly on the bumper cover where that module is (you can see it from below) and see if the message goes off. This seems to be a common part to fail and need replacing as the W166 ages.

 

Passenger sensor is corroded internally. Finding the same exact version that has the same SW and HW revisions will be nearly impossible. If i get a different version will it need adaptation?

 

Anyone know what the metal clip that holds the bracket is called or where to get them?

 

Fixed by replacing both sensors with used ones from eBay with the same HW/SW revisions.