NHTSA Owner Complaint Log
This page lists owner-reported complaints filed with NHTSA for the 2018 Mercedes-Benz GLC-Class. Complaints are unverified consumer reports submitted to NHTSA and do not by themselves prove a defect or defect rate.
Data synced from NHTSA on May 4, 2026
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
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.
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.
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.
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.
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
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.
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.
Malfunction and engine light is on. Found p052e present. Recommended replacement of crankcase breather assembly
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.
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.
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
Check engine light with code P052E.
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 .
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.
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.
Vehicle showing check engine light, connected a reader to the vehicle and it shows a code of P052E .. ( Positive Crankcase Ventilation Regulator)
P052E Error in the control panel appears a light engine
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)
Car failed to accelerate due to faulty fuel pump, fuel tank, etc. Car stopped and died several times in the middle of heavy traffic. Mercedes Benz of West Houston, Sewell Dealership, has my car that was towed to them late afternoon on 3/5/2024. I have owned a Mercedes for over 40 years and never had this occur or be scared due to the car’s lack of performance.
My car is 6 years old and has done about 30000 miles. The amplifier in the car has failed, resulting in no volume for Radio, GPS , Bluetooth devices. This seems to be a common failure in the GLC 300 based on web search.
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.
I have had to replace the faulty pcv valve in my vehicle every 11 months since I have owned it. At over $1,000 a piece and with this being a well known problem with this make of vehicle the company needs to fix this problem. There are thousands of complaints online about this. Thank you for your time. Since this is an emission component the extended warranty will not cover it.
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
Engine light error code P-052e71. The crankcase ventilation valve malfunction. This is reported by a lot of customers.. It cost about $2000 to fix this problem.
After seeing a warning light in my car's dashboard I took it in to be checked and learned the PCV intake hose had malfunctioned. This malfunction causes emissions dangerous to the environment and air quality. The condition was confirmed by an independent service center, a replacement PCV intake hose assembly ordered and installed. The warning light had been going on and off for a couple of months. When it stayed continuously on I took it in to be looked at. It was diagnosed and I had it repaired.
The contact owns a 2018 Mercedes-Benz GLC300. The contact stated that while driving at various speeds, the steering wheel malfunctioned, and became difficult to turn in either direction. The vehicle was taken to the local dealer who diagnosed that the electronic power steering module was faulty and needed to be replaced. The vehicle was not yet repaired. The manufacturer was notified of the failure, but no assistance was offered. The approximate failure mileage was 70,000.
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.
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.
I m having issue with te code po52e its annoying i fixed and still the same issue
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.
Code P052E PCV crankcase valve ventilation
What component or system failed or malfunctioned, and is it available for inspection upon request? 2018 Mercedes-Benz GLC 300 Panoramic stationary sunroof between the windshield and sunroof glass panel disbonded while vehicle was in operation and almost caused an accident on the highway. How was your safety or the safety of others put at risk? Exterior panel disbonded while in operation and almost hit vehicles behind and could have caused an accident. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes diagnosis from the dealership that panel was coming loose. Then upon picking up my vehicle, panel disbonded on the highway. Dealer is Mercedes-Benz of Atlanta South. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? No inspection only completed by local Dealership. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? Excessive wind noise inside the cabin during vehicle operation. In addition, my year, make and model vehicle has already had a recall regarding this issue, however, Mercedes did not identify my vehicle VIN number for this recall and is refusing to repair this safety issue. But the exact issue occurred on my vehicle. The NHTSA campaign numbers for the two recalls are 17V715000 (MBUSA number 2017110009) and a revised campaign in 2021 21V197 (MBUSA number 2021070010), which states “Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2018 GLC300, GLC300 4Matic, and GLC43 AMG vehicles. The fixed panoramic sunroof frontal and side plastic panels may have insufficient bonding, allowing the panels to separate during vehicle operation”. Warning signs for these recalls are “high wind noise inside the cabin” which is EXACTLY what was diagnosed on my vehicle by the dealership. Please contact Mercedes-Benz and require them to re-assess the VIN numbers identified with the recalls.
Positive crankcase ventilation regulator valve performance code P052E failed at 58k miles. Checked engine light came on after diagnostic scanner equipment .
Backup Camera randomly power cycle while the transmission is in REVERSE. It was listed for recall for 2019-2021 models vehicle and it has showed up in my 2018 GLC 300. Contacted Dealer multiple times and was told software update would have fix it. Left the vehicle with dealer multiple times and each time was told software update has been performed per manufacturer instruction. Yet the problem continue. When the incident happen, the camera screen went back to multimedia/radio/navigation screen, and the camera screen came back on. During that time, i can hear the camera pop in and out of the rear hatch (where the camera is located). it is a safety concern and definitely need a closer look at it.
The contact owns a 2018 Mercedes-Benz GLC300. The contact stated that while driving 65 MPH, the vehicle started to hesitate while depressing the accelerator pedal. The contact stated that the vehicle also started shaking and vibrating with the check engine warning light illuminated. The contact managed to pull the vehicle off the highway and had the vehicle towed to a dealer. The vehicle remained in the dealer's possession for several weeks before the contact was informed that it was discovered that the piston rings were burned and that the cylinder head was warped. The manufacturer was notified of the failure but had not yet receive a response. The vehicle was not repaired and remained in the possession of the dealer. The failure mileage was approximately 9,200.
The contact owns a 2018 Mercedes-Benz GLC300. The contact stated while driving 60 MPH, the exterior panel between the windshield and sunroof detached, creating a hazardous road debris. The vehicle was taken to the dealer, who diagnosed a failure with the exterior panel adhesive bonding agent. The vehicle was not repaired. After investigating the failure, the contact related it to NHTSA Campaign Number: 21V197000 (Structure) and 17V715000 (Visibility), but the VIN was not included. The manufacturer was notified of the failure, and a case was opened. The failure mileage was 51,000.
Vehicle is switching gears automatically from Drive to Neutral in the middle of the road, in the middle of driving, VERY dangerous situation. I cannot put in reverse sometimes it switches back to N. . It always switch his back to neutral. Thankfully no accidents. Don’t know what to do?
All of the buttons on my steering wheel including the horn stopped working. I hear a clicking noise when i turn the steering wheel and the passenger air bag light randomly goes on and off. This leads me to believe the clock spring is broken. If the clock spring is the problem, this could create an airbag malfunction causing it to not deploy when needed or randomly deploy while i’m driving.
Keep having check engine light due to fault code *P052E71 The valve for crankcase ventilation malfunction-the actuator is blocked Many of 2018 Mercedes Benz GLC 300 experienced the same issue.
My panoramic sunroof shattered while I was driving on the highway. There was a loud, sonic noise, like a gunshot and the glass shattered. There were no large trucks near me and after checking the roof, there was no object on the roof that could have caused it.
Complete engine failure after 55,000 miles determined that there was a broken piston #1 in the car. This required a complete engine replacement. This is a known problem by Mercedes with the engine model M274 there are numerous reports of the same problem in this engine over several models and years. The engine was 5000 miles out of warranty however this problem seems to occur in alot of vehicles from Mercedes with this engine. There is an active class action lawsuit in California regarding this. Mercedes seems to be ignoring this issue and or not dealing with it to date.
Rear seat belt latch plates (both driver and passenger side) retracted into the rear side paneling behind the seat. Both seat belts are now unusable. Issue occurred after rear seats were folded flat and then returned to upright position. Vehicle does not have dynamic locking tongue latch plates in the rear seats. MB dealership and MB customer care both claim that vehicle is not under NHTSA recall 18V-177 despite fitting the issue description, make & model, and production date.
At 35,000 miles the check engine light came on, error message was checked at a Mercedes dealership and read a Crankcase Vent Valve malfunction. The malfunction causes issues with acceleration and causes a high RPM idle and accelerates engine wear. After researching online, this problem has occurred to a huge number of 2015-2018 Mercedes GLC 300’s, with many people having to make this $2,000 repair every 2 years.
On May 14, 2023, with a little over 44,000 well-kept miles and under normal driving conditions, my 2018 GLC43 AMG blew smoke out the rear and soon after presented pooling oil under the transmission/engine area. Upon inspection by a reputable transmission repair specialist, AAMCO in Los Angeles, it was determined that the cause of the issue was a broken bolt head in the torque converter, resulting in significant internal damage. The bolt's failure was suspected to be the result of a manufacturing defect, as it is highly unlikely for such a crucial component to fail under normal operating conditions. The process to identify and rectify this issue involved dropping the transmission, inspecting for damage, replacing the torque converter with a new Mercedes-Benz part, and replacing all four torque converter bolts to ensure no further defects were present. Lastly, the transmission had to be resealed using a factory kit, refilled, and reinstalled. This all amounted to a significant total of $5,100 including parts and labor. This does not include the additional ~$500 spent on a rental car during the lengthy repair period.
Code P052E---crankcase Vent Solenoid Valve issue---------common issue with this model----under 65,000 miles
In May 2023 a black plastic portion of the roof blew off the car. The plastic part that blew off was around the sunroof. There was no wind or blow to the car or anything like that; there was no prior warning or error message; there were no symptoms in advance. The part simply blew off the vehicle. The part is not available for inspection. Others were put at risk because the portion that blew off could have hit them or their vehicles. If the parts obstructed someone's view, there could have been an accident. The dealer has inspected and recently repaired the vehicle and can confirm the incident. No others such as the manufacturer, police, or insurance representatives have inspected the vehicle.
Hi, Improper gear shifting. Vehicle engine light comes on with Error Code P073E, "reverse gear cannot be engaged" Vehicle would shift gear back into neutral position when put to Drive. When vehicle is able to be put in gear Reverse or Drive, a loud noise and shaking would occur. When driven, vehicle is in Limp Mode and can only go up of Gear 5. (this is a 9G Tronic, 9 gears in total) As I was backing up into street from a parking stall, I was not able to put the vehicle in Drive to proceed forward. Traffic was building up. Driver panicked. But finally was able to put it in Drive after a minute or so in the middle of the streets.
Check engine light came out for a couple of days then went off. It appeared on the dashboard on 4/21/23 and disappeared 4/24/23. The day it went off, a message appeared on the dashboard stating to check coolant levels. A mechanic ran the diagnostics and it showed up as “positive crankcase ventilation regulator valve performance”. I’ve had this vehicle for only a year and I’ve only taken it to Mercedes. Is this car going to go up in flames?
positive crank case oil separator valve part # 274-090-56-00-80 failed error code- P052E caused check engine light. Had repaired today through warranty. known issue for all Mercedes Benz. If paying out of pocket expect to spend 2,000.