Owners have filed 53 complaints
about the 2017 Mercedes Benz GLS450 with NHTSA between 2016 and 2026.
The largest single group is the engine & cooling.
Complaints filed with NHTSA, by model year. Bar colour is the FaultScore grade:
A
B
C
D
F
ungraded
What breaks on a 2017 Mercedes Benz GLS450
Every complaint is filed against a part. Follow any row for the complaints about that part alone.
Electrical System
815.1%
0 crashes, 4 fires · median 22,950 mi
Engine & Cooling
815.1%
0 crashes, 6 fires · median 40,000 mi
Other & Unspecified
713.2%
Median failure at 12,657 miles
Fuel & Propulsion
611.3%
0 crashes, 4 fires
Lights
611.3%
Median failure at 41,097 miles
Steering
47.5%
Median failure at 8,500 miles
Driver Assist & Collision Avoidance
23.8%
2 crashes, 0 fires
Seats
23.8%
Suspension
23.8%
Body & Structure
23.8%
Transmission & Drivetrain
23.8%
Median failure at 1,150 miles
Seat Belts
11.9%
Wheels
11.9%
Windows, Mirrors & Wipers
11.9%
Median failure at 135,500 miles
Brakes
11.9%
When it fails
Odometer readings owners gave when they filed. About half of all
complaints include one.
1,000 – 9,999 miles
736.8%
10,000 – 24,999 miles
421.1%
25,000 – 49,999 miles
421.1%
50,000 – 74,999 miles
15.3%
100,000 – 149,999 miles
315.8%
When owners complained
A spike years after the car went on sale usually means a part wearing
out on schedule across the whole fleet — the kind of pattern no single
owner can see from inside their own car.
May 2016peak 5Aug 2026
Complaints that involved harm
Reports where the owner recorded a crash, a fire, an injury or a death.
Palmdale, CAFire
ENGINE
On 8/20/2026 I had a vacuum leak from the intake manifold and crankcase hoses repaired at a Vic's Bimmer Shop in the city of Lancaster California. This included the replacement of the oil separator breather on the engine. I drove my Mercedes Benz 2017 GLS450 less than 100 miles and the engine lost power and suddenly turned off. I was able to pull off onto the side of the freeway and then I saw smoke coming from under the hood and my wife and I exited the vehicle, called the fire department and the car burned completed on the side of the freeway and is a total loss. I believe the oil separator leaked oil onto the exhaust pipe and engine turbo which then started the fire.
NHTSA complaint #11760731 — an unverified report by a vehicle owner.
Palmdale, CAFire
FUEL/PROPULSION SYSTEM
On 8/20/2026 I had a vacuum leak from the intake manifold and crankcase hoses repaired at a Vic's Bimmer Shop in the city of Lancaster California. This included the replacement of the oil separator breather on the engine. I drove my Mercedes Benz 2017 GLS450 less than 100 miles and the engine lost power and suddenly turned off. I was able to pull off onto the side of the freeway and then I saw smoke coming from under the hood and my wife and I exited the vehicle, called the fire department and the car burned completed on the side of the freeway and is a total loss. I believe the oil separator leaked oil onto the exhaust pipe and engine turbo which then started the fire.
NHTSA complaint #11760731 — an unverified report by a vehicle owner.
Wellesley, MACrash
FORWARD COLLISION AVOIDANCE: WARNINGS
Car did not brake when going about 5-7mph and crashed into another car.
NHTSA complaint #11713114 — an unverified report by a vehicle owner.
Car did not brake when going about 5-7mph and crashed into another car.
NHTSA complaint #11713114 — an unverified report by a vehicle owner.
Marietta, GAFire
ENGINE
On July 23, 2025, I drove my Mercedes-Benz GLS 450 to a medical appointment. After arriving, I parked near the valet station, turned off the car, and went inside to check in at LabCorp. Within two minutes, witnesses reported black smoke from the hood — followed by a violent explosion that shook the office building and triggered a multi-unit response from local fire and police departments. When I came downstairs, my vehicle was engulfed in flames. The front end was completely destroyed. Mercedes-Benz USA sent an investigator on September 8, 2025 to examine the wreck. Despite numerous follow-ups, I have received no written report, no findings, and no communication from Mercedes-Benz since that inspection detailing any relevant information. Safety Context: In March 2024, Mercedes-Benz issued Recall #24V-207, affecting 2019–2023 GLE and GLS models, citing a defective 48-volt ground connection that could cause a fire. My incident occurred in a GLS 450 model and appears consistent with this recall defect. If confirmed, this could indicate that the recall did not capture all affected VINs or that repairs were not properly executed. This incident was minutes from being fatal — and could easily have occurred on the highway or in my garage or with my 4 children inside. The lack of corporate response for over two months raises serious concerns about consumer safety, recall effectiveness, and corporate transparency.
NHTSA complaint #11693202 — an unverified report by a vehicle owner.
Plano, TXFire
ELECTRICAL SYSTEM
Fire started in the Engine and consumed the entire vehicle in less than 5 minutes
NHTSA complaint #11619840 — an unverified report by a vehicle owner.
The most recent complaints
In the owners' own words, exactly as filed with NHTSA.
Palmdale, CAFire
ENGINE
On 8/20/2026 I had a vacuum leak from the intake manifold and crankcase hoses repaired at a Vic's Bimmer Shop in the city of Lancaster California. This included the replacement of the oil separator breather on the engine. I drove my Mercedes Benz 2017 GLS450 less than 100 miles and the engine lost power and suddenly turned off. I was able to pull off onto the side of the freeway and then I saw smoke coming from under the hood and my wife and I exited the vehicle, called the fire department and the car burned completed on the side of the freeway and is a total loss. I believe the oil separator leaked oil onto the exhaust pipe and engine turbo which then started the fire.
NHTSA complaint #11760731 — an unverified report by a vehicle owner.
Palmdale, CAFire
FUEL/PROPULSION SYSTEM
On 8/20/2026 I had a vacuum leak from the intake manifold and crankcase hoses repaired at a Vic's Bimmer Shop in the city of Lancaster California. This included the replacement of the oil separator breather on the engine. I drove my Mercedes Benz 2017 GLS450 less than 100 miles and the engine lost power and suddenly turned off. I was able to pull off onto the side of the freeway and then I saw smoke coming from under the hood and my wife and I exited the vehicle, called the fire department and the car burned completed on the side of the freeway and is a total loss. I believe the oil separator leaked oil onto the exhaust pipe and engine turbo which then started the fire.
NHTSA complaint #11760731 — an unverified report by a vehicle owner.
Wellesley, MACrash
FORWARD COLLISION AVOIDANCE: WARNINGS
Car did not brake when going about 5-7mph and crashed into another car.
NHTSA complaint #11713114 — an unverified report by a vehicle owner.
Car did not brake when going about 5-7mph and crashed into another car.
NHTSA complaint #11713114 — an unverified report by a vehicle owner.
at 135,500 milesNew Canaan, CT
EXTERIOR LIGHTING
The contact owns a 2017 Mercedes-Benz GLS450. The contact heard an abnormal humming sound when the vehicle was started, and the humming sound grew louder over time. The contact believed that the humming sound was coming from the driver's side headlamp. The contact stated that the headlamp was equipped with a small internal fan to dissipate heat. Additionally, other electrical failures were occurring, and the vehicle was taken to a local dealer. The dealer diagnosed the vehicle and determined that the blower motor had failed and needed to be replaced. The vehicle was repaired; however, the humming sound returned. The vehicle was taken to the dealer on two more occasions, and the dealer replaced the timing belt and the alternator, however the failure reoccurred. Recently, while touching the door handle, the contact heard a humming sound that was very loud. The vehicle was taken back to the dealer, and it was determined that the driver's side headlamp assembly needed to be replaced. The vehicle was not repaired. The contact researched online and related the failure to NHTSA Campaign Number: 20V626000 (Electrical System, Steering, Exterior Lighting, Visibility); however, the VIN was not included. The manufacturer was contacted and confirmed that the VIN was not included in the recall. The failure mileage was 135,500.
NHTSA complaint #11710906 — an unverified report by a vehicle owner.
at 135,500 milesNew Canaan, CT
ELECTRICAL SYSTEM
The contact owns a 2017 Mercedes-Benz GLS450. The contact heard an abnormal humming sound when the vehicle was started, and the humming sound grew louder over time. The contact believed that the humming sound was coming from the driver's side headlamp. The contact stated that the headlamp was equipped with a small internal fan to dissipate heat. Additionally, other electrical failures were occurring, and the vehicle was taken to a local dealer. The dealer diagnosed the vehicle and determined that the blower motor had failed and needed to be replaced. The vehicle was repaired; however, the humming sound returned. The vehicle was taken to the dealer on two more occasions, and the dealer replaced the timing belt and the alternator, however the failure reoccurred. Recently, while touching the door handle, the contact heard a humming sound that was very loud. The vehicle was taken back to the dealer, and it was determined that the driver's side headlamp assembly needed to be replaced. The vehicle was not repaired. The contact researched online and related the failure to NHTSA Campaign Number: 20V626000 (Electrical System, Steering, Exterior Lighting, Visibility); however, the VIN was not included. The manufacturer was contacted and confirmed that the VIN was not included in the recall. The failure mileage was 135,500.
NHTSA complaint #11710906 — an unverified report by a vehicle owner.
at 135,500 milesNew Canaan, CT
VISIBILITY
The contact owns a 2017 Mercedes-Benz GLS450. The contact heard an abnormal humming sound when the vehicle was started, and the humming sound grew louder over time. The contact believed that the humming sound was coming from the driver's side headlamp. The contact stated that the headlamp was equipped with a small internal fan to dissipate heat. Additionally, other electrical failures were occurring, and the vehicle was taken to a local dealer. The dealer diagnosed the vehicle and determined that the blower motor had failed and needed to be replaced. The vehicle was repaired; however, the humming sound returned. The vehicle was taken to the dealer on two more occasions, and the dealer replaced the timing belt and the alternator, however the failure reoccurred. Recently, while touching the door handle, the contact heard a humming sound that was very loud. The vehicle was taken back to the dealer, and it was determined that the driver's side headlamp assembly needed to be replaced. The vehicle was not repaired. The contact researched online and related the failure to NHTSA Campaign Number: 20V626000 (Electrical System, Steering, Exterior Lighting, Visibility); however, the VIN was not included. The manufacturer was contacted and confirmed that the VIN was not included in the recall. The failure mileage was 135,500.
NHTSA complaint #11710906 — an unverified report by a vehicle owner.
Huntington Beach, CA
POWER TRAIN
My 2017 Mercedes-Benz GLS 450 is experiencing serious and unpredictable transmission behavior related to the valve body and shifting mechanism. The transmission sometimes fails to engage Park, shifts on its own without driver input or attempts to engage Reverse unexpectedly. On multiple occasions the vehicle has moved or rolled after being placed in Park and once it appeared to shift itself toward Reverse. This behavior is a clear safety risk as the vehicle can suddenly lose control or move unexpectedly. It happens intermittently, without any dashboard warnings and often resets temporarily after restarting the car. According to multiple owners posting on Mercedes-Benz forums (including MBWorld, BenzWorld, and Mercedes-Benz Owners Club discussions), this issue is common among GLS and other Mercedes models using the same transmission. Many owners report identical symptoms: transmission slipping into Neutral or Reverse, failure to engage Park or erratic shifting caused by a malfunctioning valve body, defective solenoids or Transmission Control Module (TCM) faults. Some have shared diagnostic codes such as P073E and P07B7 that point to reverse and park circuit errors. Mercedes technicians and independent repair specialists who have posted on these forums frequently identify the valve body assembly as the source of the issue. Common explanations include internal hydraulic pressure faults, electrical connector leaks or sensor failures inside the valve body. Owners have been quoted thousands of dollars for valve body replacements as i was billed $2300+. This problem is not isolated to my vehicle and appears to be a recurring design or manufacturing defect that affects multiple model years and platforms sharing this transmission. Because the vehicle can unexpectedly shift or fail to hold Park, it creates an immediate safety concern for both drivers and bystanders. I have video of this dangerous issue
NHTSA complaint #11695525 — an unverified report by a vehicle owner.
Marietta, GAFire
ENGINE
On July 23, 2025, I drove my Mercedes-Benz GLS 450 to a medical appointment. After arriving, I parked near the valet station, turned off the car, and went inside to check in at LabCorp. Within two minutes, witnesses reported black smoke from the hood — followed by a violent explosion that shook the office building and triggered a multi-unit response from local fire and police departments. When I came downstairs, my vehicle was engulfed in flames. The front end was completely destroyed. Mercedes-Benz USA sent an investigator on September 8, 2025 to examine the wreck. Despite numerous follow-ups, I have received no written report, no findings, and no communication from Mercedes-Benz since that inspection detailing any relevant information. Safety Context: In March 2024, Mercedes-Benz issued Recall #24V-207, affecting 2019–2023 GLE and GLS models, citing a defective 48-volt ground connection that could cause a fire. My incident occurred in a GLS 450 model and appears consistent with this recall defect. If confirmed, this could indicate that the recall did not capture all affected VINs or that repairs were not properly executed. This incident was minutes from being fatal — and could easily have occurred on the highway or in my garage or with my 4 children inside. The lack of corporate response for over two months raises serious concerns about consumer safety, recall effectiveness, and corporate transparency.
NHTSA complaint #11693202 — an unverified report by a vehicle owner.
Ronkonkoma, NY
UNKNOWN OR OTHER
Vehicle Information: Make: Mercedes-Benz Model: GLS 450 Year: 2017 Component: Visibility/Sunroof/Panoramic Glass Roof VIN: [XXX] Incident Date: [XXX] Complaint Summary: I am filing this complaint regarding a serious and dangerous safety defect in my 2017 Mercedes-Benz GLS 450. Without warning and while driving, the panoramic glass sunroof suddenly shattered and exploded, sending glass shards and debris into the vehicle cabin. My two young children were seated inside at the time, and glass pieces fell directly onto them, causing extreme distress and posing a severe risk of injury. There was no impact or external cause—the sunroof shattered spontaneously. The incident left glass scattered throughout the interior of the vehicle, including on the seats, floor, and children’s car seats. Fortunately, my children were not severely injured, but the potential for serious harm was extremely high. After researching this issue, I discovered that this is not an isolated incident. Numerous complaints have been filed with the NHTSA and other authorities regarding spontaneous sunroof shattering in Mercedes-Benz vehicles, including this model. Additionally, I understand that a federal judge recently approved a class action lawsuit addressing this exact issue, further highlighting the severity and prevalence of the defect. This is a significant safety hazard that must be addressed. I urge the NHTSA to investigate this issue further and take appropriate regulatory or enforcement action to ensure the safety of all vehicle occupants. Additional Details: No recent repairs or modifications to the sunroof or roof area. Vehicle was in motion on a clear day with no overpasses or external objects that could have impacted the roof. The noise was loud, like an explosion, followed by immediate glass breakage. I have retained photos of the damage and can provide them if needed. Requested Action: Please investigate this matter urgently. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
NHTSA complaint #11666914 — an unverified report by a vehicle owner.
Calabasas, CA
FUEL/PROPULSION SYSTEM
Vehicle check engine light came on early August 2024. Vehicle was brought in for service and checked for codes. B1F4500 Battery has excessive resistance B21059A The operating conditions of component have not been satisfied. Battery was replaced and rechecked. Po4427A Evap leak detected P04F000 Charcoal canister has a malfunction Smoke tested EVAP system to see if there was any leaks and tested the valves to make sure EVAP system was working correctly. Charcoal canister not actuating correctly so was replaced and checked. Gas cap also replaced Several days later Check engine light returns. Code continues to say "Small leak in the EVAP system." Every time the code is cleared it returns and Check Engine light returns. This has been going on for 7 months. Car cannot obtain the required SMOG inspection in California that is required for an annual registration of the vehicle. I believe the vehicle may need to be part of the Emission Service Campaign 2024030005 which has effected 16 other vehicles. Mercedes tells me that an update to the Engine Control Software will not be allowed because my vehicle is not one of the 16 vehicles that are currently effected by this issue. The issue is for the same make, model and year as my vehicle.
NHTSA complaint #11646348 — an unverified report by a vehicle owner.
Cleveland, OH
SUSPENSION
This is the 2nd time within a year my airmatic suspension system has went out while driving and I have lost control of driving my vehicle. I have paid 3900 to have the problem repaired it has not been a year and the same issue has happened. Faulty dangerous suspension system airbag suspension is dangerous and faulty.
NHTSA complaint #11628461 — an unverified report by a vehicle owner.
Plano, TXFire
ELECTRICAL SYSTEM
Fire started in the Engine and consumed the entire vehicle in less than 5 minutes
NHTSA complaint #11619840 — an unverified report by a vehicle owner.
Plano, TXFire
ENGINE
Fire started in the Engine and consumed the entire vehicle in less than 5 minutes
NHTSA complaint #11619840 — an unverified report by a vehicle owner.
Plano, TXFire
FUEL/PROPULSION SYSTEM
Fire started in the Engine and consumed the entire vehicle in less than 5 minutes
NHTSA complaint #11619840 — an unverified report by a vehicle owner.
Cleveland, OH
SUSPENSION
My suspension failed would not send any air pressure to lift my vehicle while driving my car ride was very bumpy and I loss contol.
NHTSA complaint #11577198 — an unverified report by a vehicle owner.
at 29,210 milesHuntsville, AL
STEERING
The contact owns a 2017 Mercedes-Benz GLS450. The contact stated that upon starting the vehicle after driving in a rainstorm, the power steering malfunction message was displayed. While driving approximately 70 MPH, the power steering became inoperable. The vehicle was taken to the local dealer where it was diagnosed and determined that the failure was due to the electronic power steering rack. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 17V241000 (Steering). The manufacturer was contacted and notified of the failure and the contact was referred to NHTSA Hotline for assistance. The failure mileage was approximately 29,210.
NHTSA complaint #11529734 — an unverified report by a vehicle owner.
Enid, OKFire
ELECTRICAL SYSTEM
Car destroyed by fire on March 19, 2023 while at a quick stop near Chickasaw, OK. Car was last serviced by Mercedes-Benz of Oklahoma City in December 2022. No personal injuries just a total loss of the vehicle. Cause of the fire at present is unknown. Pictures are available.
NHTSA complaint #11513006 — an unverified report by a vehicle owner.
Enid, OKFire
ENGINE
Car destroyed by fire on March 19, 2023 while at a quick stop near Chickasaw, OK. Car was last serviced by Mercedes-Benz of Oklahoma City in December 2022. No personal injuries just a total loss of the vehicle. Cause of the fire at present is unknown. Pictures are available.
NHTSA complaint #11513006 — an unverified report by a vehicle owner.
Enid, OKFire
FUEL/PROPULSION SYSTEM
Car destroyed by fire on March 19, 2023 while at a quick stop near Chickasaw, OK. Car was last serviced by Mercedes-Benz of Oklahoma City in December 2022. No personal injuries just a total loss of the vehicle. Cause of the fire at present is unknown. Pictures are available.
NHTSA complaint #11513006 — an unverified report by a vehicle owner.
Arlington, TX
SEAT BELTS
I purchased this Vehical Al from auto of Texas in carralton tx I don’t have seatbelt on the second row so I am unable to buckle my children in I have contacted dealership three time for two weeks and they have not fixed the problem I have only have vehicle for 22 day didn’t not notice the where not seatbelts until after I purchased it my niece was thrown from the seat due to no seatbelt
NHTSA complaint #11468747 — an unverified report by a vehicle owner.
Sharpsburg, GA
EXTERIOR LIGHTING
Over time, the low beam lights have faded which make it very difficult to see at night.
NHTSA complaint #11455473 — an unverified report by a vehicle owner.
Bellevue, WAFire
ELECTRICAL SYSTEM
Our car, Mercedes GLS 450, caught on fire after pulled into the garage from a short drive on local streets, which resulted a total loss on our house. After pulling into the garage, the home link didn't work when tried to use it to close the garage door. Upon coming out of the car, smoke came out from under the hood and soon after it became flame. We attempted to extinguish the fire with a fire extinguisher as it appeared with hood still closed and fire immediately came back. By the time the firefighters came, there was a full fledged fire. The fire has burned the car beyond recognition and the garage was burned too. The fire and smoke has caused a total loss on our house. There were NO warning lights or warning messages at all before smoke or fire started. Investigators hired by Mercedes Benz inspected the burnt car and concluded the fire was due to a missing oil cap. While questionable the oil cap was the source of the fire, it seems the GLS 450 didn't have a sensor for missing oil cap to trigger a warning light or warning message, which is what some less sophisticated cars have because modern engines have positive crankcase ventilation. If indeed missing oil cap could cause full fledged fire, shouldn't Mercedes put a sensor to warn the customers? There is a recall, see link below, on almost all Mercedes model cars in Jan. 2022 for the reason that the car could catch on fire. Our GLS was built just two months before the starting timeline on the recall and it caught on fire and burned our house. Could it be coincidence or did our car catch on fire due to the exact same reason on this recall? (https://www.forbes.com/sites/zacharysmith/2022/01/04/800000-mercedes-benz-owners-warned-their-cars-could-catch-fire/)
NHTSA complaint #11452172 — an unverified report by a vehicle owner.
Bellevue, WAFire
ENGINE
Our car, Mercedes GLS 450, caught on fire after pulled into the garage from a short drive on local streets, which resulted a total loss on our house. After pulling into the garage, the home link didn't work when tried to use it to close the garage door. Upon coming out of the car, smoke came out from under the hood and soon after it became flame. We attempted to extinguish the fire with a fire extinguisher as it appeared with hood still closed and fire immediately came back. By the time the firefighters came, there was a full fledged fire. The fire has burned the car beyond recognition and the garage was burned too. The fire and smoke has caused a total loss on our house. There were NO warning lights or warning messages at all before smoke or fire started. Investigators hired by Mercedes Benz inspected the burnt car and concluded the fire was due to a missing oil cap. While questionable the oil cap was the source of the fire, it seems the GLS 450 didn't have a sensor for missing oil cap to trigger a warning light or warning message, which is what some less sophisticated cars have because modern engines have positive crankcase ventilation. If indeed missing oil cap could cause full fledged fire, shouldn't Mercedes put a sensor to warn the customers? There is a recall, see link below, on almost all Mercedes model cars in Jan. 2022 for the reason that the car could catch on fire. Our GLS was built just two months before the starting timeline on the recall and it caught on fire and burned our house. Could it be coincidence or did our car catch on fire due to the exact same reason on this recall? (https://www.forbes.com/sites/zacharysmith/2022/01/04/800000-mercedes-benz-owners-warned-their-cars-could-catch-fire/)
NHTSA complaint #11452172 — an unverified report by a vehicle owner.
Bellevue, WAFire
FUEL/PROPULSION SYSTEM
Our car, Mercedes GLS 450, caught on fire after pulled into the garage from a short drive on local streets, which resulted a total loss on our house. After pulling into the garage, the home link didn't work when tried to use it to close the garage door. Upon coming out of the car, smoke came out from under the hood and soon after it became flame. We attempted to extinguish the fire with a fire extinguisher as it appeared with hood still closed and fire immediately came back. By the time the firefighters came, there was a full fledged fire. The fire has burned the car beyond recognition and the garage was burned too. The fire and smoke has caused a total loss on our house. There were NO warning lights or warning messages at all before smoke or fire started. Investigators hired by Mercedes Benz inspected the burnt car and concluded the fire was due to a missing oil cap. While questionable the oil cap was the source of the fire, it seems the GLS 450 didn't have a sensor for missing oil cap to trigger a warning light or warning message, which is what some less sophisticated cars have because modern engines have positive crankcase ventilation. If indeed missing oil cap could cause full fledged fire, shouldn't Mercedes put a sensor to warn the customers? There is a recall, see link below, on almost all Mercedes model cars in Jan. 2022 for the reason that the car could catch on fire. Our GLS was built just two months before the starting timeline on the recall and it caught on fire and burned our house. Could it be coincidence or did our car catch on fire due to the exact same reason on this recall? (https://www.forbes.com/sites/zacharysmith/2022/01/04/800000-mercedes-benz-owners-warned-their-cars-could-catch-fire/)
NHTSA complaint #11452172 — an unverified report by a vehicle owner.