2015 MERCEDES-BENZ GL550

On 8/5/2026, the power boost on the vehicle was lost while at a nearby shopping center. Braking became very difficult and it was dangerous to drive even a little distance. There were no warning lights from the vehicle. We had it towed to an independent repair shop where they determined the brake booster had failed. They did a recall check and saw that it didn't apply to our specific vehicle. They repaired it which cost $2500. Later, we did research and found that there is an expanded recall, 22V315000, which includes our year, make, and model! Our vehicle brake booster failed in the same manner as expressed in that recall. I still have the failed brake booster itself. We'd like you to have Mercedes expand the recall to include our vehicle as well as those with similarly sourced brake boosters. I called Mercedes customer service and they simply confirmed that our vehicle wasn't covered by the recall but to contact NHTSA to file a complaint to start the inclusion process.

My 2015 GL550 has 90k miles on it and is city driven, on 09/11/2023 when I was trying to pull out onto a main rd my suv hesitated and the check engine light came on, luckily traffic wasn’t heavy at the time so I wasn’t in any accidents. I called and was able to get my suv into my local Mercedes dealership for an inspection. When the suv was dropped off the check engine light had gone off but when the service center pulled up the codes it showed both turbos were bad and have to be replaced. This isn’t something that should happen to a vehicle that is regularly serviced only at Mercedes service centers, isn’t 10years old yet, never wrecked, and has less then 100k miles on it. If this had happened with heavy traffic or any other situation it could have caused a serious wreck. My suv is currently at the dealership having both turbochargers replaced at a cost of $12,000 out of pocket. I feel that Mercedes needs to look into the turbochargers used in their vehicles.

Upon receipt of vehicle, when the weather was nice, a rattle in the engine compartment appeared to take place intermittently. Upon diagnosis by a dealership, intermittent was confirmed to take place on a cold start, and not intermittently. Upon further research, it was found the rattle is related to a manufacturer's defect with the timing chain tensioner(s) and their interaction with the valves. My safety was put at risk substantially. I live in the cold upper midwest. Every start of the vehicle is a cold start, and if I risk damaging my engine at any given hour, during the dead of winter, with little to no available funds, I am at risk of hypothermia, starvation, even death. The problem, as noted in paragraph one has been reproduced by a dealer. The vehicle has not been inspected by the manufacturer in full, but the issue is known by Daimler since 2013 for certain. No warning lamps or messages are associated with the issue. The only symptom is the rattle in the engine compartment, and when appropriate tension with the timing chain is obtained, the rattle immediately goes away.

There are many models of the gl550 ranging from 2012-2015, where the second row driver side seats get stuck in a downward position. Recently it happened to me and another gl550 was in the shop at Mercedes North Houston for repair for the same issue. These are very common in this make and model and something needs to be addressed concerning the matter.

MY CAR HAS AN ONGOING PROBLEM WITH THE HVAC SYSTEM. IT GENERATES A MOLD AND MILDEW SMELL WHILE USING THE AC AND HEAT. MERCEDES SAYS THEY NO OF THIS ISSUE BUT HAVE NO PERMANENT FIX. THE SMELL IS SO BAD THAT IT IS ALMOST UN-DRIVABLE. MERCEDES DEALERSHIPS HAVE BULLETINS THAT DENOTE THE ISSUE IS KNOWN, BUT THEIR WORK AROUND ONLY TEMPORARILY IMPROVES THE SMELL. THERE IS AN OBVIOUS ENGINEERING ISSUE WITH THE HVAC SYSTEM THAT IS UNHEALTHY. THERE IS APPARENTLY THAT FORMS AROUND THE MOLD AROUND THE AC EVAPORATOR. MERCEDES HAS AN INTERNAL ALERT # TSB LI83-30-P-059119. THIS IS NOT A PERMANENT FIX AND ONLY IMPROVED THE SMELL FOR 3-4 WEEKS AND TOOK OVER TWO DAYS TO IMPLEMENT. THE SMELL OCCURS ALL THE TIME WHEN EITHER THE AC OR HEATER IS ON. THIS STARTED AT 2200 MILES AND CONTINUES TODAY (I HAVE 17K MILES NOW).