2021 Mercedes-Benz GLS 450 Forward collision avoidance Problems
- Complaints
- 2about this part
- Share
- 6%of 31 total for the year
- Median mileage
- 3,000miles
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 2 complaints about the forward collision avoidance of the 2021 Mercedes-Benz GLS 450, 6% of the 31 complaints for this model year. Where a mileage was given, the median is 3,000 miles.
Fewer than 15 complaints name this part, so treat the figures as a rough indication only.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“On four occasions my car has stalled while in traffic very early in my ownership and then it happened again today with my family in the car and nearly caused an accident. The entire dash lights up with every warning when it happens. Sometimes the check engine light comes on after I shut the car off and restart it. My Mercedes dealer has had it in multiple times for this reason. The last time it was in for this (May of 2022) they reprogrammed the entire car. It happening again today has really made me lose a lot of faith in the vehicle, especially since we purchased it for the safety factors. …”
NHTSA complaint #11500946, filed 2023-01“The contact owns a 2021 Mercedes Benz GLS450. The contact stated while driving 75 mph with the cruise control engaged, the vehicle decelerated to 45 mph than to 15 mph. On another occasion, while driving 80 mph, the vehicle independently decelerated to 45 mph. There was no warning light illuminated. The vehicle was taken to the local dealer however, the mechanic was unable to duplicate the failure. The vehicle was not diagnosed nor repaired. The contact stated that the cruise control and speed assistance feature provided erroneous information. The manufacturer was notified of the failure. …”
NHTSA complaint #11426426, filed 2021-07, 3,000 milesRelated service bulletins
- 11018204May 2, 2025Complaint Hand detection system not operating correctly / vehicles with code 266 Fault message in instrument cluster: "Active Emergency Stop Assist not available" "Active Lane…
- 11005334Jul 15, 2024Complaint Hand detection system not operating correctly / vehicles with code 266 Fault message in instrument cluster: "Active Emergency Stop Assist not available" "Active Lane…
Forward collision avoidance: other model years
Other parts of the 2021 Mercedes-Benz GLS 450
14 complaintsOther or unknown
8 complaintsEngine
3 complaintsLane departure
3 complaintsSeats
2 complaintsFuel system
1 complaintsSeat belts
1 complaintsSteering
1 complaintsBody and structure
1 complaintsTires
1 complaintsTransmission and drivetrain
1 complaintsVehicle speed control
1 complaints
← All problems reported for the 2021 Mercedes-Benz GLS 450
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 31, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology