2023 Mercedes-Benz GLC 300 Electrical Problems

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.

NHTSA ID

11725658

Incident

Jan 9, 2023

Mileage

12,000 mi

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)

NHTSA ID

11725254

Incident

Mar 18, 2026

I purchased a brand new GLC 300 on May 25, 2023. By June 2, 2023 I was already stranded due to a 12V battery electrical system failure. Since then I have been stranded 8 total times and the vehicle has been in the service department 14+ times for repeated electrical issues (8 of those visits were related to the same 12V battery electrical system failures. The battery was reportedly replaced in 2024-shortly thereafter I began experiencing issues with the collision assist malfunctioning. The alarms would sound seat belt tighten and brakes lock up while driving on the interstate. The theft deterrent alarm wound sound in the middle of the night without provocation. The panoramic roof would malfunction. The air vent disintegrated. In August 2025, the collision assist malfunctioned causing the vehicle to steer off the road resulting in a blow out. It has not been driven since.

NHTSA ID

11722368

Incident

Jun 2, 2023

check engine light continues to turn on and off, response from dealer maintenance is this issue is temperature related and just keep driving, not sure how this makes for an effective or safe functioning of a warning light also seems like it can lead to unnecessary trips to and costs at the maintenance garage. This has been a multiple time issue since purchase of vehicle.

NHTSA ID

11629834

Incident

Dec 3, 2024

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.

NHTSA ID

11618304

Incident

Jul 12, 2024

The care sends a message that the battery is low. Then the check engine light comes on till we drive the car for awhile. The first time this happened I took it to the dealer and they said they could find nothing wrong with it and was giving no readings. It has continued to happen a lot. The battery should not be going down if it not being used. There has to be a problem. This has been going on for over a year. The dealer where we bought the car called today about service and said there was a recall about the battery, but when I call MB they said there was not recall?

NHTSA ID

11615647

Incident

Sep 15, 2024

Loss of propulsion at highway speeds with subsequent failure of digital light system at night resulting in injury crash

NHTSA ID

11614976

Incident

May 9, 2023

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.

NHTSA ID

11609329

Incident

Aug 15, 2024

The contact owns a 2023 Mercedes-Benz GLC 300 W4. The contact stated that when his wife was parking the vehicle at approximately 5 MPH and when she depressed the brake pedal, the vehicle stalled. The contact stated that his wife said that the brake pedal failed, and the instrument cluster was black. The contact stated that his wife had observed that the brake warning had been illuminated before the instrument cluster failure. The contact stated that his wife jumped the curb and crashed into the wall of a building. The contact stated that the front end of the vehicle was crushed, and the hood was damaged. The contact stated that the front headlights and front bumper were also crushed. The contact stated that the windshield was cracked as well. The contact stated that his wife was unhurt despite the air bags not deploying. The contact stated that the police were called and they issued a report. The contact had called his dealer who referred him to a body shop. The contact had the vehicle towed to a local body shop. The vehicle was not diagnosed by a dealer or independent mechanic. The vehicle damage was being repaired. The contact had researched online and related the failure to NHTSA Campaign Number: 24V115000 (Electrical System). The manufacturer was informed of the failure. The failure mileage was approximately 7,000.

NHTSA ID

11607936

Incident

Jul 11, 2024

Mileage

7,000 mi

There is an active recall for my vehicle Mercedez Benz GLC 300W4 for which I was NOT NOTIFIED BY THE DEALER AND MANUFACTURER. The recall states that certain 80A fuses installed might not meet production requirements. As a result, a contact interruption or an increased triggering resistance might occur. In this case, systems connected to the fuse might become inoperable. Among others, the vehicle might lose propulsion without warning, restraint functions or the instrument cluster might be impaired, increasing the risk of a crash and injuries. In addition, a risk of fire cannot be ruled out. An authorized Mercedes-Benz dealer will replace the respective main fuse box on the affected vehicles. The following is the SAFETY RISK associated with this recall. As a result, a contact interruption or an increased triggering resistance might occur. In this case, systems connected to the fuse might become inoperable. Among others, the vehicle might lose propulsion without warning, restraint functions or the instrument cluster might be impaired, increasing the risk of a crash and injuries. In addition, a risk of fire cannot be ruled out. I have noticed that check engine light turning on at times while driving which might be due to this fuse malfunctioning. Please take appropriate action and support my case. I can provide more details if required. Thank you.

NHTSA ID

11601017

Incident

Jul 2, 2024

The contact owns a 2023 Mercedes-Benz GLC300. The contact stated that while he and his wife were loading the trunk of the vehicle, the trunk door independently lowered and struck his wife on the head. The contact stated that the failure occurred frequently. The contact stated that he had previously had a concussion and was concerned about being struck on the head by the trunk during the failure. The dealer was made aware of the failure, and the vehicle was diagnosed; however, the cause of the failure was not yet determined. The dealer informed the contact that the automatic open and close feature on the trunk could not be disengaged. The vehicle was not repaired. The manufacturer was made aware of the failure and a case was opened. The failure mileage was approximately 10,000.

NHTSA ID

11586735

Incident

Mar 14, 2024

Mileage

10,000 mi

Vehicle would not start, indicator displayed check owners manual, battery low. Vehicle towed to dealer

NHTSA ID

11585120

Incident

Apr 20, 2024

Check engine light on, according to Mercedes Benz problem related to 48 V mild hybrid,I took twice car to the dealership ,they can’t reset check engine lights GLC 300 2023 With 3500 miles

NHTSA ID

11568277

Incident

Dec 20, 2023

This vehicle has now had three episodes where warning lights came on for no apparent reason. There have been two episodes of "Check Engine Light" coming on, the first with less than 1000 miles on the vehicle. It was driven to the dealer and they checked finding no problems and said not to worry about it. The second about two months later with an indication of "Excessive engine Temperature", but the engine was cold and just started, the fan was running very fast, but otherwise the vehicle was operable. Again, the dealer could find no problem and said to ignore it, but return if it recurred. Two months later, check engine light on again. Currently at the dealer for service for a third time. No faith in the reliability of this car with the reports of this leading to engine stalls and failure to start in other cars.

NHTSA ID

11563288

Incident

Jan 3, 2024

2023 Mercedes Benz GLC 300. Several Electrical, Braking, Collision, Check Battery related issues noted. At approximately 500 miles on vehicle battery system began sending critical voltage error messages to notification app after the vehicle had been turned off. --Owner recharged battery on front terminals. At various intervals, check engine light would come on while driving, sometimes for days at a time. Sometimes for less than an hour, sometimes for a day or so but not long enough to get into a MB Dealer.---MB has less than 5,000 Miles. At approximately, 3800 miles owner received notification on phone app that the vehicle had been involved in a crash while the vehicle was sitting in a parking spot in an open parking lot with no other vehicles surrounding it. Owner was looking at the vehicle at the time of the supposed crash. Owner walked around and assessed vehicle and called MB. MB online advisors advised to take car in to have inspected for a crash. At 5400 miles vehicle was parked for less than 30 minutes. Owner returned to car and attempted to start. All warning lights, sensors and bells began going off. Check engine, 12Volt electrical system, braking and emergency braking system warning, SOS warning, etc and etc. Owner cycled through all warnings. Vehicle believed it was on when it was off. Vehicle would not start. Owner then received critical 12 Volt battery low warning messages on phone App for car. Owner tried to call MB Me Connect but the operators could not hear owner over loud alarms. Vehicle would not allow owner to lock the car to leave to get assistance. Tow called. Vehicle would not electronically switch to Neutral to be pushed to better location for attempt at jump start. Front terminal would not jump start vehicle but left connected to charge. Vehicle boost used with jump start to finally start car. Next morning Check engine light still on, App sent message battery was low despite battery charger being on car overnight.

NHTSA ID

11547469

Incident

Sep 29, 2023

The contact owns a 2023 Mercedes-Benz GLC300. The contact stated while attempting to start the vehicle, the message "12 Volt Battery Failure, Vehicle Inoperative" was displayed. Later, the contact was able to start the vehicle, but the check engine warning light remained illuminated. Eventually the light shut off and the vehicle operated normally. The vehicle was taken to the local dealer who performed a diagnostic test and identified multiple communications errors however, the cause of the errors was not yet determined. The vehicle was not repaired. No further information was available. The manufacturer was notified of the failure. The failure mileage was 400.

NHTSA ID

11545150

Incident

Jul 9, 2023

Mileage

400 mi

Car would not start warning lights on dash unable to start car

NHTSA ID

11541998

Incident

Aug 31, 2023

Hatch closes or opens when bumper cover is depressed accidentally causing injuries by smashing on top of head and crushing hands. Contact us for a video recording of an event.

NHTSA ID

11540517

Incident

Aug 24, 2023

While driving on highway at 75 mph, the car began slowing down and an alert on the screen said "Stop. Switch off vehicle". Then the alert on the screen showed that the 48 volt system needed to be recharged. The car would not start and had to be towed to the dealership. The dealership says the car was out of gas, but the gauges did not indicated that the fuel was empty, so they will reset all of the sensors, but they still do not know why the car turned off and could not be restarted. They are checking the software because they cannot find anything wrong.

NHTSA ID

11538784

Incident

Aug 8, 2023

Brand new car that had less than 1500 miles on it, one day went to start it while 20 miles away from home and error messages in dash and beeping "48V battery error, do not change transmission position, reduced functionality of driver assistance features...etc." and car would not start, could not turn steering wheel.

NHTSA ID

11538778

Incident

Jul 30, 2023

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.

NHTSA ID

11538722

Incident

Jul 16, 2023

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.

NHTSA ID

11537315

Incident

Aug 6, 2023

The moon roof will not close. There is also a sloshing sound of water in an unidentified area, it has not rained. The blind spot monitor function of the digital light projection works intermittently and is barely visible marking on the roadway. The exit assist also does not activate the ambient lighting when opening door and car Is approaching in the travel Lane. Digital lights have jagged output light beam and they are the illuminating the roadway as advertised.

NHTSA ID

11536675

Incident

Jun 7, 2023

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.

NHTSA ID

11536674

Incident

May 5, 2023

Unexpectedly and without any indication or warning, at [XXX] on [XXX] I experienced multiple system failures/engine light/critical warning lights/. Transmission error message states do not shift into gear, take for service. Engine check light on. Car would not start, car was unable to be put into park. Door alarm for transmission not in park was alarming audible. After car shut off and attempt to put into park the car would not engage into park and the car electronics malfunctioned, would not stop alarming despite off, multiple error messages, including traction control inoperative, blind spot inoperative, digital light inoperative, check the 48V batter Error, and other messages toggling on. Dealership Bergeron Mercedes made aware of problem on 8/04 And was told no appointments or lands car available and to drop off Monday sans appt, name on wait list. VIN [XXX] . This is a common problem on all of the forums regarding this first what new models hear 23 releases. I was unable to put the car into park and the parking brake could not hold in place/trusted. Also, the digital light malfunctioned and high beam assist and digital light. Became inoperative due to failed wheel level sensor. Car has less than than 5K miles /less than 3 months old. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11536672

Incident

Aug 4, 2023