Collision prevention assist goes off randomly
Thread Starter
Junior Member
Joined: Sep 2003
Posts: 42
Likes: 2
From: Sweden, Europe
S500 w222, W205
Collision prevention assist goes off randomly
I have a year 2016 built in march. The collision prevention assist goes off randomly, showing the red triangle and makeing a loud beep. It seems like it's happening more often than before. Every time this happened the road has been free from other cars or people so it's strange that it is happening.
Anyone else experiencing this? I didn't fint it searching the forums.
Anyone else experiencing this? I didn't fint it searching the forums.
Mine seems to always be working as intended.
The only time it goes off where it doesn't need to is when there is a car in a shoulder turning lane in the opposing direction, or a car turning off the main road.
The only time it goes off where it doesn't need to is when there is a car in a shoulder turning lane in the opposing direction, or a car turning off the main road.
Junior Member
Joined: Jan 2015
Posts: 50
Likes: 0
From: Sydney Australia
C250 W205 in Polar White
I also experience this issue many times and after I took the car into the dealer for another issue. I told them about this problem as well and they reset the onboard computer in my car.
Now two weeks after the reset I haven't had one falsely going off! (fingers crossed)
Aside note, I was talking to the MB technician about this issue and he told me he had a guy came in and complaining he almost got rear ended on the motorway by another car behind when the collision prevention assists went off in his CLA45 due to the auto brake engaging; bringing the car to a sudden stop!!
Geezus...now that's scary!
Now two weeks after the reset I haven't had one falsely going off! (fingers crossed)
Aside note, I was talking to the MB technician about this issue and he told me he had a guy came in and complaining he almost got rear ended on the motorway by another car behind when the collision prevention assists went off in his CLA45 due to the auto brake engaging; bringing the car to a sudden stop!!
Geezus...now that's scary!
Member
Joined: Sep 2015
Posts: 139
Likes: 16
From: Detroit area
2015 S550 Coupe; 2025 EQS 450 SUV
I've noticed that the material used to fill in cold weather-caused cracks in the road sometimes triggers the sensors when I'm going up/down inclines.
The material is mildly reflective, and I believe that causes the collision warning to go off. It's a small price to pay, considering that AEB technology is still in its infancy.
If your collision warning goes off on straight, flat roads, that's when I'd bring it in to the dealer.
The material is mildly reflective, and I believe that causes the collision warning to go off. It's a small price to pay, considering that AEB technology is still in its infancy.
If your collision warning goes off on straight, flat roads, that's when I'd bring it in to the dealer.
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Senior Member
Joined: Jan 2016
Posts: 276
Likes: 21
C350e
I seen this message (or a similar one) twice in the 10 months I own it. Once when it was snowing (snow buildup) and once during heavy rain. Both fully acceptable in my opinion.
But your situation is not normal.
Member
Joined: Apr 2016
Posts: 206
Likes: 15
From: san francisco
c class
I want get it looked at when I go in for service B my car is also noisy as if front windows aren't all the way closed, just had them replace the headrest cause there was a shaking inside after the button broke
I feel like I go there too many times which is why I'm waiting on this one, I just switch it off every time I drive
What worries me is that it seems to kill traction control when it happens then it doesn't accelerate which pisses off people at stop signs ( Bay Area drivers aren't that patient)
Thread Starter
Junior Member
Joined: Sep 2003
Posts: 42
Likes: 2
From: Sweden, Europe
S500 w222, W205
Thank you for your replies! It seems to be like I was expecting, other people are experiencing similar "problems".
I've read in another secion of the forums about Collision prevention assist going off in a different car model. Someone got their sensors realigned and maybe it is possible to make the sensors less sensitive.
I will bring this problem up to my dealer when I go there to get the acoustic glass installed.
My fear is what was mentioned by sir c250:
"...I was talking to the MB technician about this issue and he told me he had a guy came in and complaining he almost got rear ended on the motorway by another car behind when the collision prevention assists went off in his CLA45 due to the auto brake engaging; bringing the car to a sudden stop!"
Scary!
I've read in another secion of the forums about Collision prevention assist going off in a different car model. Someone got their sensors realigned and maybe it is possible to make the sensors less sensitive.
I will bring this problem up to my dealer when I go there to get the acoustic glass installed.
My fear is what was mentioned by sir c250:
"...I was talking to the MB technician about this issue and he told me he had a guy came in and complaining he almost got rear ended on the motorway by another car behind when the collision prevention assists went off in his CLA45 due to the auto brake engaging; bringing the car to a sudden stop!"
Scary!
Member
Joined: May 2016
Posts: 145
Likes: 7
2016 C450
As others have said, take it in if it is happening too often. That said, when this first happened to me I pulled over and called up the manual for troubleshooting. I am paraphrasing, but basically "clean the sensors" and it started immediately working again.
Senior Member
Joined: Jan 2016
Posts: 276
Likes: 21
C350e
Let's hope that MB service will check if the sensors are dirty before they start replacing or adjusting components then.
Member
Joined: Jul 2015
Posts: 89
Likes: 1
2016 AMG C63S
When I took delivery of my car, the dealer warned me that the collision detection would go off randomly, sometimes due to lamp posts or trees while turning, others due to elevation changes in the road. There have only been two times when the car actually applied the brakes, and that was in stop and go traffic, so they were justified.
Other than that, there are countless times when it would go off when nothing was around, but I soon realized that it was good that the car is over sensitive than under, especially in an instance when it ends up being necessary.
Other than that, there are countless times when it would go off when nothing was around, but I soon realized that it was good that the car is over sensitive than under, especially in an instance when it ends up being necessary.
Banned
Joined: Jun 2013
Posts: 46
Likes: 3
2015 C400 4Matic Black
collision prevention assist inoperative
2015 C400, mine would do this 3 or 4 times during long road trips.
after about 2-3 minutes it would start working again "collision prevention assist is now availabel" would show in the display.
I took a look at the front radar unit in the grill and noticed the cable going to the connector was extremely tight. I mean really tight.
I managed to pull some slack to the connector and havent had an issue since.
after about 2-3 minutes it would start working again "collision prevention assist is now availabel" would show in the display.
I took a look at the front radar unit in the grill and noticed the cable going to the connector was extremely tight. I mean really tight.
I managed to pull some slack to the connector and havent had an issue since.
Junior Member
Joined: Mar 2019
Posts: 42
Likes: 23
e400 wagon
Hi All,
I started a thread so we can get a head count on people with this issue, across different platforms. If your car's having this problem, please post here:
https://mbworld.org/forums/mercedes-...ml#post7833418
I started a thread so we can get a head count on people with this issue, across different platforms. If your car's having this problem, please post here:
https://mbworld.org/forums/mercedes-...ml#post7833418
