What 98 owners told NHTSA about the 2018 Mercedes-benz Glc-class

Component Failure: The vehicle is equipped with the M274 2.0L turbocharged engine, which suffered a major internal mechanical defect. An authorized Mercedes-Benz dealership diagnosed the vehicle at 79,504 miles with a malfunction in the crankcase ventilation system alongside severe internal defects, quoting a total repair estimate of $9,851 to perform extensive engine work. Safety Risk: This known manufacturing defect involves premature failure and cracking of the pistons, which poses an immediate safety hazard due to potential catastrophic engine failure and sudden, complete loss of motor power while driving at highway speeds. The manufacturer has failed to offer an extended warranty or recall for this known issue on the 2018 model year.

NHTSA ODI 11741952

Safety Issue: Infotainment display screen produces scrambled pixels during Apple CarPlay navigation while driving. Description: When Apple CarPlay is connected and navigation is in use, the vehicle's infotainment display screen suddenly produces scrambled pixels, rendering the map and display unreadable. This malfunction occurs without warning while the vehicle is in motion, creating a dangerous visual distraction for the driver and uncertainty of where and when to turn or exit. This is a known, recurring issue. On January 7, 2021, I brought this problem to Mercedes-Benz of Indianapolis (Repair Order #624027), where a firmware update was applied and the issue was allegedly resolved. The fix has not proven permanent — the problem has since recurred and continues to present a safety hazard while driving. Despite this being a widely documented issue affecting numerous Mercedes owners, Mercedes-Benz has not issued a recall or technical service bulletin that I am aware of. My dealer is requiring a diagnostic fee of over $250 to inspect the vehicle, and Mercedes-Benz USA customer service has been unreachable. Requested Action: I am requesting that NHTSA investigate this issue and consider whether a Technical Service Bulletin or recall is warranted given the safety implications of a sudden display malfunction while driving.

NHTSA ODI 11732752

While driving on interstate 4 in Florida with our grandchildren going approximately 70 mph the sunroof on our 2018 Mercedes GLC just exploded no object came into the vehicle and while glass came into the vehiclenot all the glass that made up the sunroof came into vehicle suggesting a pressure issue as apparently blew out

NHTSA ODI 11723228

The contact's friend owns a 2018 Mercedes-Benz GLC 300. The contact stated that while the owner was driving at an undisclosed speed, the accelerator pedal was depressed, but the vehicle failed to accelerate as intended, and the gear shifter independently shifted to neutral(N). No warning lights were illuminated. In addition, the contact stated that the failure was persistent. The contact stated that the owner forced the gear shifter out of neutral(N). The vehicle was taken to the dealer, where it was diagnosed that the transmission control unit had failed and needed to be replaced. The vehicle was not repaired. The contact related the failure to an unknown recall, but the VIN was not included in a recall. The manufacturer was made aware of the failure, and a case was filed. The contact was advised to contact the NHTSA Hotline to report the failure. The failure mileage was unknown.

NHTSA ODI 11708077

The contact owns a 2018 Mercedes-Benz GLC300. The contact stated that while driving at various speeds, the vehicle shifted into gear initially without warning. The contact stated that while stopped at a light, the vehicle shut off with the "Transmission Malfunction Stop" message displayed on the instrument panel. The contact was unable to move the vehicle, and the vehicle was towed to an independent mechanic. The mechanic ran a diagnostic test on the vehicle and initially stated that the front drive wheel sensor was defective; however, the contact was then informed that there were no issues with the sensor. Neither the dealer nor the manufacturer was notified of the failure. The vehicle was not repaired. The failure mileage was approximately 90,000.

NHTSA ODI 11702561

I have P052E71 error code. It’s a crankcase ventilation malfunction. Seems to be a common issue reported widely online on various forums. Mercedes should place a recall on this. The car has 55k miles on it.

NHTSA ODI 11699931

The contact owns a 2018 Mercedes-Benz GLC300. The contact stated that while operating the vehicle, the message "Front Air Bag Malfunction" was displayed, and the horn became inoperable. The vehicle was taken to the local dealer who diagnosed that the steering column and air bag clock spring were faulty and needed to be replaced. The vehicle was not yet repaired. The manufacturer was notified of the failure and informed the contact that the VIN was not included in NHTSA Campaign Number: 17V627000 (AIR BAGS). The contact stated that the vehicle had experienced the failure listed in the recall. The failure mileage was 60,000.

NHTSA ODI 11698503

I had the engine light come on and took it to the dealership. They quoted me over 8 thousand dollars to fix. I took it to a repair shop that works on luxury cars and they fixed it for less than 1000 dollars. I had to have the transducer fixed in the turbo in my engine and when they did that they found oil in the electrical harness. That was caused by the oil seperator. They told me that it was a manufacture defect that has been well documented and to take it back to Mercedees Benz. They looked and found the oil but said my car did not produce a code and could not fix it. We escalated it to corporate that reviewed my case and said they still would not fix until it produced a code. Mercedees implemented an extended warranty for my car back in 2022 for emissions. They said they would cover it if it produces a code. I researched this problem and it said it posses a risk to me, my passengers and the public if it quits running or causes a fire. Corporate said its not a problem yet.

NHTSA ODI 11698021

While pulling into a parking spot with my foot hovering above/on the break, the car lurched forward as if someone had floored the gas pedal. As my foot was already on the break, I slammed down onto the break and the car came to a stop, several feet ahead of the top of the parking spot, and into the woods. I called roadside assistance for the vehicle to be towed to the dealership for repair, as I did not find it safe to drive it. The dealership was unable to replicate the issue, but they told me that due to the severity of the issue, they weren't supposed to check it themselves. Instead, I needed to report a case to Mercedes Corporate and the communication from here would be handled directly between corporate and myself. It's been over three weeks since this occurred, and I have not received communication that the car has been tested further, or any next steps. The car is at the dealership. It's also important to note that this same issue also happened months before, while backing out of a parking spot in reverse. I didn't report it because it was a confusing thing to happen and I couldn't believe a car would gas on it's own. When it happened a second time, I knew it was a problem. This was not a case of user error or the floor mat being in a wrong position. What component or system failed or malfunctioned, and is it available for inspection upon request? Speed control / yes How was your safety or the safety of others put at risk? The car spontaneously accelerated and could have caused harm if people or structures were in its path. Has the problem been reproduced or confirmed by a dealer or independent service center? Has not been reproduced Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Not that I know of Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? No

NHTSA ODI 11687525

The car does not go into drive from reverse and will sometime automatically shift itself from a low drive gear (D1) into Neutral without warning. After this happens - the car also can't get back into D1. It takes about 20 seconds for the car to shift back into a Drive gear and it will jolt into D3 violently. This has been a scary experience on many occassions - especially at red lights when this happens and we can't get the car out of neutral for some time. This was diagnosed by mercedes dealership near us as a fawlty sensor in the transmission. It is extremely expensive to fix and is specific to mercedes meaning it has to be done by a MB dealership. We applied for good will for assistance but were denied. The car has been maintained very well - this is not a maintenance issue but a specific sensor failure of a mercedes sensor in the transmission. We are thankful no one was hurt - we had our 8 year old daughter in the car when stalling out several times at red lights and it's been a very scary situation.

NHTSA ODI 11676731

Malfunction and engine light is on. Found p052e present. Recommended replacement of crankcase breather assembly

NHTSA ODI 11669031

I was backing out of my driveway and was putting the car in Drive when the airbag located in my steering wheel deployed without a reason. The car has not been inspected by anyone as of today. I was told there was a warning but that it was not of immediate attention in November of 2024.

NHTSA ODI 11648715

The contact owns a 2018 Mercedes Benz GLC 300. The contact stated while attempting to park, a loud clanking noise was coming from the steering wheel as the air bag warning light illuminated. The vehicle was taken to the dealer where it was diagnosed that the clock spring in the steering wheel which caused the steering wheel to fail and the steering module needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and referred the contact to the NHSTA Hotline for assistance. The approximate failure mileage was 62,700

NHTSA ODI 11635080

Vehicle experienced transmission shifting issue after having driven for a period of 15 - 20 minutes, with engine oil temp reaching above 103/105 degrees C, transmission won't shift into Drive. Automatically pops into Neutral. Other times engine will stall, required complete restart. This creates hazard for operator and cars following behind as driver needed to steer vehicle out of the way of traffic while in Neutral. Independent MB repair shop and dealership scanned vehicle and identified with code P073E code. Dealer upgraded TCM control module software, and wanted to replace valve body in hope of remedy the problem. They were not 100% certain problem will be fixed. Independent repair shop indicated MB need to issue a recall for this problem, as they have seen many owner faced with the same problem. This is a big safety issue with problem of the transmission control module. Problem can be reproduced.

NHTSA ODI 11632530

I have engine light on and when I scanned it, I got a error code P052E For crankcase vent valve issues. It is most common problem with Mercedes-Benz Glc .

NHTSA ODI 11630856

Transmissiongoes into neutral while driving car at times. sometimes it will not go back into gear No movement of car on freeway potential of being hit from behind. problem reproduced, inspected by independent shop not inspected no lights

NHTSA ODI 11621613

Check engine light with code P052E.

NHTSA ODI 11604980

when the car is in drive it will stop like it is in park unable to drive or put in reverse. This happens at random times on the road. The car will then skip gears and go into Neutral then skip an again on its own and go into drive.

NHTSA ODI 11592323

The contact owns a 2018 Mercedes-Benz GLC300. The contact stated that when the driver's side seat belt was buckled, the seat belt alarm chimed as if the seat belt was not buckled. The contact had to buckle and unbuckle the seat belt several times before the warning chime stopped. The contact had taken the vehicle to a local dealer who diagnosed the vehicle and determined that there was no issue with the seat belt system. The vehicle was not repaired. The contact stated that the failure was intermittent. The contact researched online and related the failure to NHTSA Campaign Number: 19V788000 (Seat Belts) however, the model year was not included. The manufacturer was informed of the failure. The failure mileage was approximately 48,000.

NHTSA ODI 11590569

The contact owns a 2018 Mercedes-Benz GLC300. The contact stated while driving approximately 30 MPH, the air bag warning light illuminated. Additionally, the contact stated that he observed a rattling noise emanating from the steering column while making right turns. The vehicle was taken to an independent mechanic where it was diagnosed that the clockspring needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 72,000.

NHTSA ODI 11586069

P052E Error in the control panel appears a light engine

NHTSA ODI 11580321

Vehicle showing check engine light, connected a reader to the vehicle and it shows a code of P052E .. ( Positive Crankcase Ventilation Regulator)

NHTSA ODI 11580186

Mercedes Benz C300 P052E positive crankcase ventilation regulatory valve. Check engine light is on and the replacement is expensive. This is known issue, discussed in most MB forums. Please have it as manufacturers recall. By the time you come across this I may have already paid it some place to get it fixed... but want to help others. Thank you. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11579834

I brought my vehicle in to get serviced because the check engine light came on and I was told it was CODE PRESENT P0521E71 VALVE FOR CRANK CASE VENT. HAS MALFUNCTION / BLOCKED. I was told I have warranty on it so Mercedes of Massapequa took the car to fix.I was told the part was fixed but oil was found on my engine computer from the crank case vent malfunctioning but the warranty won't cover it although it was a direct result of a part that was covered part and had caused the damage.They gave me my car back and my car is worse it has problems starting it requires multiple cranks and the air conditioner has a fuel smell when turned on and I am unable to pass my vehicle inspection because my check engine light it still on.I spoke to the corporate office and they said because I have too many miles they can't do a courtesy and honor the cost and referred me back to the dealer and the dealer told me they will bring the cost to fix the computer leak to $6000 although it was due to a faulty part on their behalf .I am beyond upset my car is non longer reliable or safe to drive.Mercedes of massapequa ignored all my calls after they gave me back my vehicle that was worse after they claimed they fixed it.

NHTSA ODI 11579424

The windshield washer pump failed due to the Sam unit. Failing I was in the mountains, started my car the windshield wiper malfunction light came on the wipers worked for a minute, so I turned them off, drove over the pass and tried to use my wipers, and they did not work. The back wipers did work. I took my car to my mechanic in Cheyenne, who discovered that’s the SAM unit Ruined the windshield washer pump. No one else has inspected it other than my mechanic. I have learned that there are others complaining of the same issue online. This is a dangerous issue when you are driving in a storm with no windshield wipers. My mechanic believes this should be a recall issue, and so do I. The Mercedes dealership said my mechanic, a faulty Sam unit to replace the Sam unit that went out. Now my car is throwing all kinds of codes and the back windshield wipers do not work.

NHTSA ODI 11577478