There are 1 stored owner reports matching the speed control & cruise leading-label group for the 2020 Mercedes-Benz GLS-Class in our NHTSA-sourced dataset. These are unverified consumer reports and may not reflect confirmed defects.
This group counts stored reports whose component label starts with one of this site's matching prefixes, ignoring case. Each matching report counts once within the group. Components mentioned later in the label or only in the narrative are not searched. How component counts work
Loaded 1 of 1 matching reports.
Open the full vehicle complaint log (all categories)The adaptive cruise control feature of this vehicle on various highways [XXX] , [XXX] and the [XXX] ) and in various locations while traveling at highway speeds has mis-read speed limit signs and aggressively decelerated(I assume by using its regenerative braking) to as low as 35mph while traffic is moving at 65+mph. The dealership was unable to duplicate this issue. No faults are displayed to the driver. I do not know if rear brake lights are illuminated when this occurs. This is an aggressive and scary deceleration with no warning. I fear a rear end collision is likely. No one aside from the dealership has inspected this vehicle INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
NHTSA source checks for this vehicle year
Checks are recorded separately for each dataset, not for the whole page. Dates use UTC. A missing check date does not mean no records exist.
Vehicle import recorded: Aug 31, 2026. This is the stored import date, not confirmation that every source was successfully refreshed.