There are 1 owner-reported engine complaints for the 2020 Mercedes-Benz GLS-Classin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
On a long road trip - about halfway on [XXX] - received an error message on 48v system malfunction - immediately called nearest Mercedes dealership (Richmond Va) to schedule a service - while on the line received an engine overheating pull over and shut it off message - at this point vehicle deaccelerated over riding my control of vehicle speed. Had to navigate from far left lane to right hand emergency lane at 40 mph - very dangerous maneuver as losing power. Vehicle was towed and received a 48v software update - software that deaccelerates the vehicle with no override for safety is a real problem 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.
Data synced from NHTSA on Apr 25, 2026