We accepted delivery of our brand new vehicle in May 2021 from the dealer. In July 2021, the vehicle became completely disabled due to failure of the 48 volt battery. In October 2021, the dealer replaced 48 volt battery failed again causing the vehicle to become completely disabled. In December 2023, our 3rd replacement 48 volt battery failed. Each time the vehicle is out of service for a week or…
2021 mercedes-benz GLS-Class electrical problems
severe 14 complaints filed with NHTSA · avg repair $850
Complaints
14
Recalls
0
Crashes
0
Avg fix
$850
What owners are reporting 8 most recent
Vehicle has just over 31k miles. ON multiple occasions, the vehicle randomly shuts off and displays a 48 volt battery error on the screen followed by a check engine light. This has happened in the middle of a busy intersection and at 75mph on the interstate. Each time it does this, I have taken it to a Mercedes dealer for repair/troubleshooting. THey perform the Mercedes required steps to repair t…
Incident 1: May 2022 Vehicle was sitting in driveway overnight and would not start in the morning. Had a 48V battery warning on. Towed to dealership. Said it was a delay software update. Incident 2: August 2022 Was driving 35mpg down the road where a warning sign comes up. Then shortly after the car slows down to around 15mph and would not speed up anymore. Towed to dealership. Dealership did …
Car would not start, 48 volt system failure
Car shut off while driving. Would not restart. 48 volt battery failure, needed software update
Car turned on by itself, then 2 days later would not start. 48v battery system needed software update
Vehicle would not start on 3 separate occasions. The instrument panel indicated it was the 48v battery. Had it towed to Mercedes dealership to have 48v battery replaced.
1. Unknown, smoke started coming from under the passenger side seat, car is a complete loss. 2. Smoke damaged my lungs, there was a large amount of exploding glass, and it could have led to a structure fire. 3. Not applicable 4. In process, but it was recalled for this issue 5. No
Common questions
How serious is the electrical problem on the 2021 mercedes-benz GLS-Class?
It's a meaningful issue. 14 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $850.
At what mileage does the electrical typically fail?
Mileage data is limited for this issue. Owners report failures across a wide range, suggesting cause is more about driving conditions and maintenance than mileage alone.
What does it cost to fix?
Independent shops typically charge around $850 for electrical repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to electrical?
No active recalls currently cover electrical issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Severity ratings are derived from reported crashes, fires, injuries, and fatalities.
Repair cost estimates are independent-shop national averages and may differ in your area.
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