There are 1 owner-reported engine complaints for the 2021 Mercedes-Benz GLS-Classin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
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. I read online that there are many others who have experienced this. Some say it is related to the 48V battery. I don't care what Make or Model or how expensive it is, a new car should NOT stall in traffic and should be looked into. Thank You.
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.
Data synced from NHTSA on Apr 25, 2026