GLE400d adaptive cruise control speed problems
#1
![Angry](https://mbworld.org/forums/images/icons/icon8.gif)
Hi guys. I have a GLE400d 2022, and I've had the same speed recognition problem which only started two weeks after getting it from new.
Mine will over read and under read both here in the UK and throughout Europe. I've been told by Mercedes it is a 'GPS thing' because it relies on the GPS signal being uninterrupted to get the correct information. If it doesn't then you can get spurious readings.
Not good, and liable to get you into trouble if not careful, and given its a 'premium' car from a supposed 'quality' manufacturer then I'd say not a good omen or reflection on Mercedes.
Mine will over read and under read both here in the UK and throughout Europe. I've been told by Mercedes it is a 'GPS thing' because it relies on the GPS signal being uninterrupted to get the correct information. If it doesn't then you can get spurious readings.
Not good, and liable to get you into trouble if not careful, and given its a 'premium' car from a supposed 'quality' manufacturer then I'd say not a good omen or reflection on Mercedes.
#2
Super Member
![](https://mbworld.org/forums/images/ranks/veteran_army.png)
![](https://mbworld.org/forums/images/ranks/veteran_navy.png)
cryoman,
Welcome to the forum.
GPS has built in and inherent fault.
Most GPS has a system called FDE which stands for Fault Detection and Exclusion.
They also have RAIM, and predictive RAIM, which stands for Remote Autonomous Integrity monitoring.
RAIM basically triangulates on GPS satellites and determines if there are enough and or if they are properly positioned to provide accurate location data.
Theoretically all GPS for automotive installation would have the same problems you are describing.
From what I gather, you think these problems are exclusive to the brand, or are more pronounced in comparison to other manufacturers.
Is that about right?
Welcome to the forum.
GPS has built in and inherent fault.
Most GPS has a system called FDE which stands for Fault Detection and Exclusion.
They also have RAIM, and predictive RAIM, which stands for Remote Autonomous Integrity monitoring.
RAIM basically triangulates on GPS satellites and determines if there are enough and or if they are properly positioned to provide accurate location data.
Theoretically all GPS for automotive installation would have the same problems you are describing.
From what I gather, you think these problems are exclusive to the brand, or are more pronounced in comparison to other manufacturers.
Is that about right?
#4
Member
The speed limit recognition is mainly done by the camera - and IIRC uses the GPS maps as a fallback, but that wouldn't care about occasional signal interruptions. It's also blind as a bat, and will regularly miss speed limit signs, or pick up irrelevant signs. Automatic cruise speed adaptation is a menace and was disabled within an hour of me getting the vehicle...
Oh, and here in Belgium it's utterly useless because, for some reason, it doesn't know the difference between Flanders and Wallonia, and thus thinks "end of speed limit" is 90 km/h everywhere, even though it's 70 km/h in Flanders. Good job, Mercedes.
The vehicle speed is purely done by wheel sensors, not sure where GPS would come into that?
Oh, and here in Belgium it's utterly useless because, for some reason, it doesn't know the difference between Flanders and Wallonia, and thus thinks "end of speed limit" is 90 km/h everywhere, even though it's 70 km/h in Flanders. Good job, Mercedes.
The vehicle speed is purely done by wheel sensors, not sure where GPS would come into that?