Mercedes-Benz
Gl-Class

My 2015 Mercedes-Benz GL63 AMG has suffered two separate ECU failures caused by oil migrating through the engine wiring harness. The first failure occurred at ~42,600 miles in 2020, and the second at ~59,000 miles in 2023. Both times, the vehicle developed misfires, check-engine warnings, and drivability issues that could have led to stalling at highway speeds. On both occasions, the vehicle has been completely disabled. Repairs required replacement of the wiring harness, ECU, sensors, and fuse box, costing over $5,600. This is a hidden, recurring defect that poses a safety risk and financial burden. The vehicle does not feel safe or reliable to drive, and dealer support and guidance is non-existent. I have been afraid to drive to the point that it has only accumulated 3,000 additional miles in the last two years.

To Whom It May Concern: I am writing to formally request the National Highway Traffic Safety Administration’s assistance regarding a critical safety defect in my 2015 Mercedes‑Benz GL 450 (M278 engine). I purchased this vehicle in October 2024 with 76,000 miles, and it now has about 87,000 miles. Alarmingly, I recently received a quote for $13,000 to repair a camshaft failure and extensive electrical damage. I was unaware of these issues when I purchased this car. I bought it under the illusion that it would be a safe vehicle for me and my children. As a single parent and teacher I invested in this vehicle what I could afford and felt I had purchased a safe, reliable vehicle. I am devasted to have a proposal for repairs in excess of $13,000 from a Mercedes dealership who diagnosed the car. This caused me to do some research and I found the GL450 has a known and widespread defect. I also found, that this causes the cam shaft to need to be repaired and that this is not normal wear-and-tear—it is a systemic design vulnerability common across GL450 models. This can result in the engine seizing from what I was told and that directly poses a substantial risk when driving. From what I found this is a common issue with this car and I did not know that when I purchased it. This is a design flaw, not a misuse of the vehicle. Finally, a $13,000 repair to make this car safe and road ready is astronomical and is not aligned with a normal maintenance cost- manufacturer accountability is warranted here. I respectfully request that the NHTSA: Investigate whether a safety recall or extended warranty program is appropriate for this known defect in the GL450. Require Mercedes‑Benz to provide a comprehensive repair solution for me and repair this defect in my car's engine under the manufacturer's expense. And finally, for Mercedes to make customers affected by this aware of this engine defect and long term risks associated with this issue. Respectfully, Alyssa Begin

The contact owns 2015 Mercedes-Benz GL450. The contact stated that the check engine warning light was illuminated. The vehicle was taken to the dealer, where DTC code: P060A00 was retrieved. The dealer determined that the solenoid valve had failed and needed to be replaced. The contact related the failure to TSB Number: 37 13 17 2029027/8. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 119,000.

On Mercedes GL350, the trunk/ hatch door will not open from outside. It just stopped working. Therefore, I tried to open it from inside, but there is no manual latch inside to open the trunk/ hatch door. It is a safety issue. The dealer, Mercedes Benz of Richmond, 8225 West Broad Street, charged $235 to open the hatch door. The dealership billed total $1322.48 (after 10% discount $1219.66) to replace the latch and its motor. Kindly help the GL350 owner to have latch installed inside open the door in case of emergency.

See attached document for complaint

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.

The contact owned a 2015 Mercedes-Benz GL450. The contact stated that the vehicle was in the dealer for 12 days for an oil change. The contact's son drove the vehicle 2 days later, at an undisclosed speed when the vehicle started smoking from the engine. The contact's son pulled over when the vehicle caught fire completely. The fire marshals came out to extinguish the fire, there were no injuries. No police report was filed. The vehicle was not diagnosed nor repaired by an independent mechanic or dealer. The manufacturer was made aware of the failure. The failure mileage was approximately 110,000. The consumer stated the vehicle was taken for routine maintenance and twelve days later returned without an oil change. Oil was added to the vehicle and it started smoking.