2023 Mercedes-Benz GLC 300 Problems
Owner-reported complaints filed with NHTSA, grouped by component
Data refreshed
What this page shows
Everything below is an owner-reported complaint submitted to NHTSA about the 2023 Mercedes-Benz GLC 300, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
Reports by component
Ranked by how many owner reports name each component category
- Electrical3034.9%
- Engine1517.4%
- Driver assistance1112.8%
- Exterior lighting1011.6%
- Brakes55.8%
- Fuel system55.8%
- Body & structure44.7%
- Powertrain (other)33.5%
- Steering22.3%
- Visibility11.2%
Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.
Each component in detail
What the reports in each category say, in the owners' own words
Electrical
Reports naming the electrical system — wiring, battery, charging, control modules, infotainment and electrical accessories.
From owner reports, verbatim
The contact owns a 2023 Mercedes-Benz GLC300. The contact stated that while driving at an undisclosed speed, the speed limit warning system failed to function as intended. The contact stated that while driving 60 MPH, the Heads-up Display (HUD) illuminated a red light and an unknown message about driving too slowly was displayed. The contact stated that the red light illuminated and flashed intermittently. The vehicle was taken to the dealer, and the contact was informed that the failure was common with the vehicle. The vehicle was not repaired. The contact stated that the failure persisted. The contact asked if the speed limit warning system could be deactivated, and the dealer was informed that it had to be approved by the manufacturer. The manufacturer was made aware of the failure. The contact was referred to the dealer for assistance. The contact stated that the dealer and the manufacturer offered no assistance. The failure mileage was approximately 12,000.
There are two issues 1) Unsure of the exact date, but about a year or two ago we were driving our car and the car's automatic break system went into effect on a typically busy, 3 lane road despite there not being any cars in front of our vehicle. We took it into the dealership, who confirmed the issue and told us that sometimes the automatic brake mis-identifies the metal plates in the roads to be vehicles. Had there been a car driving behind us at the time this was happening, it could have been a major accident as the speed limit on that road was 45mph. Additionally we had our [XXX] in the car. There were no warning lamps, messages or symptoms of the problem prior to failure. 2) Recently we have been having a warning sign on our car that says the 12v battery is low, even though it should not be. Historically this would tell us to drive our car around so the battery wouldn't die, but this would sometimes turn on even after a 30+ minute drive. It was turning on every single time we turned the car off, so we brought it into the shop. While in the shop, the dealer provided us with a brand new GLC 300. I took this GLC 300 to my son's daycare to drop him off and when I returned to the car I received an error message "48V battery service required" and could not turn on the vehicle. This brand new vehicle left me stranded. While I was safe at my son's daycare, this has caused me to have significant concerns around the safety and reliability of these GLC300s. We are planning on taking our 2023 GLC 300 on a 6 hour road trip with our [XXX] old and [XXX] old and I am very concerned about the car not starting if we stop for gas. What if we get stranded in a small city along the way? INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Engine
Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components.
From owner reports, verbatim
Vehicle has a significant engine oil leak without being driven. Engine oil electronic meter still shows engine oil to be in "Ok" range. Vehicle is 2023 with only 19680 miles and is rarely driven till the last 2 months. Other 2023 Model Year MB GLC300's manufactured at the same Bremen Germany plant are already being recalled for engine and fuel leaks, however, this one is not on the list. This vehicle is also the 2.0L Inline 4 engine and may be the same engine as the others being recalled. The others are recalled due to an imperfect seal between the high pressure fuel pump and the tandem oil pump. My vehicle is leaking engine fluid, likely oil at a significant rate without having been driven in any unsafe manner or much use.
First of all, this is a new car produced in 2023. Since I bought it, the engine has shown alarms more than four times. Every time I went to the 4S shop, no problems were found. Today, the engine still shows a yellow alarm. Secondly, the brake disc makes a loud noise when I park the car and then start the accelerator. Mercedes-Benz has not paid attention to these problems. I think it greatly affects driving safety.This car has been sent to the 4S store many times, but the inspection has always failed. The above-mentioned problems with the car have always existed. I sincerely request your help in solving them.
Driver assistance
Reports naming forward-collision avoidance, lane keeping, back-over prevention, cruise control and related electronic driver-assistance systems.
From owner reports, verbatim
There are two issues 1) Unsure of the exact date, but about a year or two ago we were driving our car and the car's automatic break system went into effect on a typically busy, 3 lane road despite there not being any cars in front of our vehicle. We took it into the dealership, who confirmed the issue and told us that sometimes the automatic brake mis-identifies the metal plates in the roads to be vehicles. Had there been a car driving behind us at the time this was happening, it could have been a major accident as the speed limit on that road was 45mph. Additionally we had our [XXX] in the car. There were no warning lamps, messages or symptoms of the problem prior to failure. 2) Recently we have been having a warning sign on our car that says the 12v battery is low, even though it should not be. Historically this would tell us to drive our car around so the battery wouldn't die, but this would sometimes turn on even after a 30+ minute drive. It was turning on every single time we turned the car off, so we brought it into the shop. While in the shop, the dealer provided us with a brand new GLC 300. I took this GLC 300 to my son's daycare to drop him off and when I returned to the car I received an error message "48V battery service required" and could not turn on the vehicle. This brand new vehicle left me stranded. While I was safe at my son's daycare, this has caused me to have significant concerns around the safety and reliability of these GLC300s. We are planning on taking our 2023 GLC 300 on a 6 hour road trip with our [XXX] old and [XXX] old and I am very concerned about the car not starting if we stop for gas. What if we get stranded in a small city along the way? INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
1. Rear Hatch hands free system - closes unexpectedly while loading or unloading car without using feet to trigger system. Hatch will close down and trap driver in the rear, causing bruising on driver and requiring assistance to push hatch back up. Has been into dealer multiple times since this is HUGE risk to animals or small children exiting out of the rear. Dealer finally disabled hands free system. 2. Lane change assist/blind spot warning - Auto believes there's a vehicle in the lane to either side and will stop car from changing lanes, when actually there isn't a vehicle there. Has caused several close calls due to signaling to change lanes the car will then try to pull back into previous lane. Warning light remains on the side mirrors even when there are no vehicles in the lane. This is especially hazardous while driving at night and in less than optimal weather conditions.
Exterior lighting
Reports naming headlights, tail lights, turn signals and other exterior lighting.
From owner reports, verbatim
Second time the rear left tail light not working properly. The parking light stay on after turning vehicle off at time it turns off. The light assembly was replaced by dealership less than a year ago. The light assembly was defective according to the dealership vehicle was purchase 10 prior.
I have taken the delivery of this car on May 2023 and has been having many issues including but not limited to rear seatbelt malfunction that needed replacement. Recent major issue is constant 'check engine light on' for various issues. Below is the 'F' and 'I' items from 'initial quick test log' as of [XXX] and also attaching detail log file. No resolution or action has been taken after several trips to the dealership in past couple of weeks and not being able to drive due to safety concern. N127 - Control unit "Drivetrain" (PTCU) -F- N73/3*1 - Electronic ignition lock - Central gateway (EZS) -I- E1n9 - Left headlamp (SG-SW-L) -I- E1n15 - Light source module control unit front left (LSM-CU-VL) -f- E2n15 - Light source module control unit front right (LSM-CU-VR) -f- E1n14 - Digital headlamp control unit front left (DHLS-CU-VL) -f- E2n14 - Digital headlamp control unit front right (DHLS-CU-VR) -f- A66 - Battery module (48 V battery) (BM48) -F B29/13 - Left rear short range radar (NBR-LR) -I- B29/14 - Right rear short range radar (NBR-RR) -I- A40/11 - Multifunction camera (MFK) -I- N62/3 - Parking system (PARK) -I- A40/8 - Central display (ZAN) -f- N133/1 - Instrument cluster (IC) -f- INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Brakes
Reports naming service brakes, the antilock braking system, brake hoses, master cylinders or the parking brake.
From owner reports, verbatim
See attached document for complaint.
GLC 300 was purchased new on May 25, 2023. Multiple 12V battery errors, check engine indicators, and rear hatch closing on owner starting the first week of ownership. 48V battery and Main Fuse Box were replaced. Multiple recalls were addressed. Most significant issue related to false collision avoidance incidents on two occasions that resulted in dangerous situations and extreme stress on the occupants. First occurrence was on July 12, 2024. Driving approximately 40 mph on two lane road near a school that was not in session. There were no surrounding vehicles, pedestrians or obstacles. Vehicle beeped, seatbelts locked, and speed forced to 10 mph. Took vehicle to local MB dealership who attributed the vehicle’s response to proximity to a school zone. Vehicle was not checked for fault codes. Second occurrence was on August 19, 2024. Driving 55 mph on major highway and a truck entered the merge lane to the right. The truck was travelling at reduced speed and remained in the merge lane showing no effort to merge into vehicle’s lane. Vehicle had violent sudden deceleration with beeping alerts, locking seatbelts and reduced speed to 10 mph. Driver and passenger experienced symptoms of whiplash. It was fortunate that there was no vehicle travelling immediately behind the vehicle. Vehicle was driven to MB dealership for analysis. The vehicle had been driven 6,177 miles in 15 months. Service manager indicated there were no fault codes so no maintenance was warranted. Owner viewed the vehicle as dangerous due to false collision avoidance issues that put passengers and others at risk. The owner sold the vehicle to the MB dealership.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Fuel system
Reports naming fuel storage or delivery — tanks, pumps, lines, injectors and fuel leaks.
From owner reports, verbatim
Car has software issue putting drivers at risk until the update is provided. Response to problem from manufacturer is to drive the car or wait until such time as a solution is developed. this is the 3 issue in less than a year the car's fuel uptake system is interrupted putting drivers at risk when pulling out into traffic or needing normal acceleration expected from a normally functioning car. How long will Mercedes get away with this before someone is killed
Loss of propulsion at highway speeds with subsequent failure of digital light system at night resulting in injury crash
Too few reports in this category for a page of its own — they appear in the full complaint list.
Body & structure
Reports naming the vehicle structure, frame, body panels, doors, hood and trim.
From owner reports, verbatim
1. Rear Hatch hands free system - closes unexpectedly while loading or unloading car without using feet to trigger system. Hatch will close down and trap driver in the rear, causing bruising on driver and requiring assistance to push hatch back up. Has been into dealer multiple times since this is HUGE risk to animals or small children exiting out of the rear. Dealer finally disabled hands free system. 2. Lane change assist/blind spot warning - Auto believes there's a vehicle in the lane to either side and will stop car from changing lanes, when actually there isn't a vehicle there. Has caused several close calls due to signaling to change lanes the car will then try to pull back into previous lane. Warning light remains on the side mirrors even when there are no vehicles in the lane. This is especially hazardous while driving at night and in less than optimal weather conditions.
The contact owns a 2023 Mercedes-Benz GLC300. The contact stated that while the vehicle was parked, and the contact and his wife were removing groceries from the rear of the vehicle, the tailgate was independently lifted due to the design of the keyless entry feature. The contact and his wife continued to remove items from the rear of the vehicle and the tailgate sensor became enabled, and the tailgate closed inadvertently, striking the contact's wife on the head. The contact's wife sustained a knot on the head that remained for a week. The vehicle was taken to the dealer. The contact was informed that the feature could not be deactivated unless the contact chose to deactivate the entire keyless sensor feature. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was made aware of the failure and the contact was informed that the option would be to deactivate the entire keyless sensor. The failure mileage was approximately 1,000.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Powertrain (other)
Powertrain reports that are not specifically the engine or transmission — driveshafts, axles, transfer cases and differentials.
From owner reports, verbatim
Vehicle sputter and coolant malfunction and engine light came on while driving ( 12-26-23) Took to dealer for some “ update”. After a few weeks of driving the vehicle sputter again and engine light came on again on the (1-19-2024 ) Drove home turned off , loud noises came from engine area. Tried to restart and failed a few times so we let it’s sit for almost an hour and it’s started again with engine light still on . Towed to Mercedes dealer and after long and frustrating times a week later per dealer it’s was the 48v hybrid battery that defective/ non functional. So far we been forced to drive the vehicle “as is” since Mercedes-Benz USA refused to let local dealer to order and replace the 48v hybrid battery. It’s been 2 weeks all informations we get from dealership is that we have to wait for Mercedes to come up with new software to update to which no time frame have been provided as to when software available. We’re experiencing terrible gas mileage MPG with the 48v battery basically non functional as moment
VEHICLE SHUT DOWN WHILE DRIVING. WARNING LIGHTS ILLUMINATE, CHECK ENGINE LIGHT, DO NOT SHIFT INTO GEAR WARNING, 48V BATTERY WARNING, ETC. WOULD NOT STOP ALARMING. COULD NOT SHUT OFF CAR. COULD NOT PUT CAR INTO PARK. COULD NOT START CAR. WARNING BUZZER WOULD GO OFF ENTIRE TIME. CAR WAS ONLY ABLE TO BE STARTED WHEN REMOTE START REQUEST WAS INITIATED WHEN CAR WAS IN THIS MODE, CAR WAS STARTED BUT THEN SHUT OFF 10 SECONDS LATERS APP STATES, “CHECK ENGINE LIGHT ON” WIL SHUT OFF THE CAR. CAR BACK TO NORMAL AFTER EVENT APPROX 60 MIN BUT CHECK ENGINE LIGHT REMAINS ON.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Steering
Reports naming the steering system — racks, columns, power-steering assist and steering linkage.
From owner reports, verbatim
Loss of propulsion at highway speeds with subsequent failure of digital light system at night resulting in injury crash
This 2023 GLC, a newly redesigned model, has a number of issues. The two most severe are the adaptive speed limit and the lane keeping assist. I had to disable the traffic sign recognition feature because I was on I-95 in Maryland where the posted speed limit was 65. The car abruptly slowed me down to 35 because it saw an exit sign speed limit but I was not on the exit. I was lucky the car behind me didn't hit me. A warning would be good but to brake the vehicle for a speed limit sign seems problematic. The more serious issue is the lane keeping assist. The car is supposed to show green markers when I'm above 37MPH and on a marked road. Normally, one turns red and eases the car back into the lane if I drift. There are 3 settings and mine is set to provide the most warning. If the system works (it sometimes does) I am already on the line at the alert. Typically, it could care less where I am in relation to road markings and will let me drift across lanes with no warning whatsoever. I took the car in to the dealership several times for this. The first time, they said "it's designed so you can't trick it." I didn't buy that. I then took it our for a drive with the service manager. He said "it detected steering input". I then let it drift across the road marking while removing my hands from the wheel and it provided no warning whatsoever (no turn signal use to disable the function). I asked him if he saw steering input that time. He said "I need a video of this". This issue has supposedly been sent to the engineers in Germany but this problem existed when new and it's been weeks with no resolution. This is a backup system but it is something I certainly paid for and would like to know it works should I actually need it. All testing was done in a safe manner and not around traffic. I can only attach pictures but I have videos as well. The dash should not be showing green lane markings on both sides in any of these screenshots from videos.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Visibility
Reports naming windshields, glass, wipers, defrosters and mirrors.
From owner reports, verbatim
Digital Light Inactivean High Beam Assist messages Also, when you engage the inoperative warning the actuates blinker it off [brights/high blinds beams even when drivers. auto adaptive setting is day with lights off see the high beam blue light on with headlight malfunctions vehicle 248595-Connected LEst sensor FaultY batterse causing, adaptive found fault C151E29 currentiy present charger invalid performed SDS for • f 0.00. Performed guided test, found vaLue Rear level value of 8149 Unplugged sensor • спескеа Ins no corrosion or loose pins. With different fault for from front left unevagged, was stored "no signal" • sensor. Plugged sensor back in, and sensor started reading correctly. Available Ordered new sensor; Customer to return when part Service Digital Light Inactiveand High Beam Assist inop erative . At this time.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Elsewhere on this vehicle
Data sources
- NHTSA Office of Defects Investigation — owner-reported complaints and the components recorded on them
Data on this page last refreshed .