C450/C43 AMG
Sponsored by:
Sponsored by:

Cruise Control Speed Randomly Changes

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old 03-05-2020, 06:24 PM
  #1  
MBWorld Fanatic!
Thread Starter
 
djrabbi's Avatar
 
Join Date: Sep 2009
Location: NOMAD
Posts: 7,655
Received 56 Likes on 46 Posts
CLS550 4Matic, C43, E350, ML350
Cruise Control Speed Randomly Changes

So when I am on a straight shot road with a 70 Speed limit, I put it at 80. Maybe 4-5 min on cruise control, it decreases to 45MPH or some other random speed. I am thinking the GPS in the car is thinking it is on another road, maybe a local road and taking that speed limit. I was going 80 today and car went to 15MPH! The car braked so hard and I freaked out. I did see in the dash it said 15MPH but no way it is 15MPH on a highway.... any other issues?
Old 03-05-2020, 06:44 PM
  #2  
Super Member
 
stockbmw's Avatar
 
Join Date: Dec 2016
Posts: 797
Received 138 Likes on 121 Posts
2018 C43
Originally Posted by djrabbi
So when I am on a straight shot road with a 70 Speed limit, I put it at 80. Maybe 4-5 min on cruise control, it decreases to 45MPH or some other random speed. I am thinking the GPS in the car is thinking it is on another road, maybe a local road and taking that speed limit. I was going 80 today and car went to 15MPH! The car braked so hard and I freaked out. I did see in the dash it said 15MPH but no way it is 15MPH on a highway.... any other issues?
Does you car comes with adaptive cruise control?

Clean your windshield where the sensors are at top and see if it improves tomorrow.
Old 03-05-2020, 09:05 PM
  #3  
MBWorld Fanatic!
 
superswiss's Avatar
 
Join Date: Nov 2018
Location: San Francisco Bay Area
Posts: 8,709
Received 3,998 Likes on 2,664 Posts
2019 C63CS
Assuming you have the driver assistance package, then the adaptive cruise control will by default automatically adopt the recognized speed limit. This can be turned off in the vehicle settings. Your speed limit sign recognition is picking up incorrect speed limits, perhaps from a sign on an adjacent road or there's something wrong with your camera or as mentioned above, dirt on the windshield blocking part of the camera. I have the automatic speed limit adoption turned off. I don't find it very useful here in the USA. It was helpful in Europe where speed limits change frequently and are enforced with speed cameras, but it occasionally picked up a speed limit sign it shouldn't have and then slowed down unexpectedly. It didn't happen that often, so having it turned on was worth it to avoid speeding tickets. I can still manually adopt the current speed limit by pressing Resume at any point.
Old 11-09-2023, 07:18 PM
  #4  
Junior Member
 
Steve_22GLE450's Avatar
 
Join Date: Jan 2022
Location: Massachusetts
Posts: 40
Likes: 0
Received 12 Likes on 9 Posts
GLE450
How is it turned off in the settings specifically? Thank you
Old 11-09-2023, 07:32 PM
  #5  
MBWorld Fanatic!
 
superswiss's Avatar
 
Join Date: Nov 2018
Location: San Francisco Bay Area
Posts: 8,709
Received 3,998 Likes on 2,664 Posts
2019 C63CS
Originally Posted by Steve_22GLE450
How is it turned off in the settings specifically? Thank you
Read the owner's manual. It's in there. There are various speed adaptation settings for cornering, speed limits etc. that you can turn on/off. It's all under the Assistance settings for DISTRONIC. The below is for MBUX. COMAND has similar settings.



Old 11-09-2023, 08:01 PM
  #6  
Junior Member
 
Steve_22GLE450's Avatar
 
Join Date: Jan 2022
Location: Massachusetts
Posts: 40
Likes: 0
Received 12 Likes on 9 Posts
GLE450
Indeed it is in the manual under Assistance\Traffic Sign Assist\Limit Adoption (which I've not turned off!). This is the menu on my 23 GLE for anyone else who may be interested.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Cruise Control Speed Randomly Changes



All times are GMT -4. The time now is 05:41 PM.