Frequent Blind Spot System Inoperative Message
Thread Starter
Junior Member
Joined: May 2019
Posts: 18
Likes: 10
From: Vancouver, BC
18' AMG GTC, 03' CLK430, 15" GL350
Frequent Blind Spot System Inoperative Message
Hello All,
I've been getting pretty frequent and random "Blind Spot System Inoperative Messages" while driving my 2015 GL350. The blindspot system just stops working and the lights in the mirror turn solid yellow while it is out. It happens at completely random times and also completely random intervals. Also, for the first time, today along with the blind spot message it said that the "Pre Safe Breaking System Inoperative" like I said, I think this is the first time its happened, for sure the first time I've noticed this one however it may have been happening before I can't recall exactly. Anyways, asking for help if any of you have had similar issues with your GLs and how I should go about diagnosing and fixing this issue.
Thanks!
I've been getting pretty frequent and random "Blind Spot System Inoperative Messages" while driving my 2015 GL350. The blindspot system just stops working and the lights in the mirror turn solid yellow while it is out. It happens at completely random times and also completely random intervals. Also, for the first time, today along with the blind spot message it said that the "Pre Safe Breaking System Inoperative" like I said, I think this is the first time its happened, for sure the first time I've noticed this one however it may have been happening before I can't recall exactly. Anyways, asking for help if any of you have had similar issues with your GLs and how I should go about diagnosing and fixing this issue.
Thanks!
Senior Member
Joined: Jul 2007
Posts: 283
Likes: 102
From: Maryland
S 550, S65 Coupe
I had a similar issue that started that way and then the turn signals eventually would stop working. Both would reset when you restart the car. Turned out to be the turn signal control unit. I just replaced the whole assembly under the steering wheel. That fixed both issues.
Thread Starter
Junior Member
Joined: May 2019
Posts: 18
Likes: 10
From: Vancouver, BC
18' AMG GTC, 03' CLK430, 15" GL350
Very helpful response thanks for that. Just wondering if you ever got the "Pre Safe Breaking System Inoperative" message? I'm trying to figure out if replacing the same control unit would fix both of my issues or not. Thanks again!
Senior Member
Joined: Apr 2012
Posts: 356
Likes: 66
2012 ML350 Bluetec, 2015 GL350 Bluetec
I had such issue with my ML but the setup is the same. Per the owner's manual it's normal to have such issue if you are driving in heavy rain, or your bumpers are too dirty. If the error comes in very often then there's something wrong in the system. You need a Star or Xentry system hooked up to figure out the real issue. I did it with my Xentry from China. Just read the two front door modules. On mine it appeared the computer thought the triangular light on the passenger side view mirror is broken, although it lights up fine. The mirror heater was not working so I just bought a used mirror glass on ebay and replaced it and it was all good. A new one is not too bad I checked getmercedesparts.com and the passenger side mirror is $156 but the driver side is $660 due to the auto dim.
Member
Joined: Jun 2018
Posts: 150
Likes: 23
2017 GLS450, 2013 GL450, RIP 2011 GL450 (totalled)
Same here. I've had 'Blind Spot Inoperative' on and off for years and would only trigger when car in drivers side blind spot. Had codes for 'implausible' signals from the radar sensor. Replaced the sensor with a used one, no luck. The code 'The signal of component 'M21/1e2(left Blind Spot Assist warning lamp)' is implausible.' was also present after replacing sensor in bumper (code was present before as well). Replaced side glass mirror with replacement off eBay for $140 and it fixed the issue. Still getting codes related to mirror heater but seems to be finicky so ignoring.
