Jun 3, 2026Engine
While driving the vehicle the engine started running rough, check engine light illuminated and it would not accelerate above 40 mph. There are 29,100 miles on the vehicle, it's been serviced on schedule by Mercedes and is owned by me since new. It is especially concerning due to the acceleration topic which could have been catastrophic if I were trying to merge into traffic. Dealer service say the camshaft bearing needs to be replaced. It seems this is very premature for the mileage on the vehicle.
NHTSA ODI 11741752
Aug 2, 2025Transmission & drivetrainSpeed controlEngine
•Incident Details: •Both sudden shutdown incidents •“12V Battery” warning (first incident) •“Stop - Switch Off Vehicle” warning (second incident) •That it happened with children in the car on a tollway Safety Concerns: •Loss of power steering/braking •Risk of collision •Repeated failures on a 1-year-old vehicle
NHTSA ODI 11677934
Dec 9, 2024LightsEngine
Attention Assist System Suspended notification comes on randomly on vehicle while driving, rendering driver defenseless with regard to safety warnings that would otherwise be in effect, such as blind spot assist, attention assist, which are vital components for safe driving. This has happened on numerous occasions, most recently on 12/06/2024 while driving under destination route guidance. It has also happened when car was stopped to retrieve mail at residence mail box and, at other times for no apparent reason, while driving. Each time when engine was restarted the dashboard read 'System suspended' and continued to do so until car was returned to dealer. This vehicle was purchased on 12/21/2023 and with less than 350 miles began repeated problems with warnings, the first of which was "Check engine"on 02/02/2024, as car was running rough. Car was repaired(dealer determined cause was electrical/software error, fault code) yet before driving out of the dealership the same 'check engine' warning reappeared and vehicle had to be returned to service that same day for the same problem. Since that date in 2023, this vehicle has had numerous seemingly computer related issues that render it unreliable as to the safety devices this vehicle features that should always be maintained. On 03/21/2024 with less than 950 miles the fans remained running after shutting vehicle off and a message appeared stating" cooling system malfunction/reduced drive performance" with a red triangle on dashboard. Dealer determined the cause was 'SOFTWARE" At this point I am concerned that this vehicle is over engineered with computerized options that randomly fail. On another occasion the lights on one side may have been on overnight. The lights (courtesy lights) were on on the right side overnight in garage. My safety is continuously at risk whenever a warning appears.I replaced my GLK specifically to have Blind Spot Assist, PRE-safe, Attention Assist, Active distance assist and other features.
NHTSA ODI 11629760
Nov 14, 2024Transmission & drivetrainElectrical systemEngine
When stopped at a light or stop sign, Vehicle will Jerk forward as If hit from behind. Very surprising and dangerous. Very intermittent. The has happened many times. Vehicle will at times have rough downshifts. Ie. overdrive (9th) to (8th) gear. also intermittent. This has happened multiple times. Vehicle was taken to the dealer twice for a total of 50 hours in the shop. The first service time no problem was found, diagnostics did not show problem. Aug 22 to Aug 30, 2024. The second service time Oct 3 to Nov 14, 2024. Problem was duplicated by the technician. Vehicle diagnostics still did not show a problem. Technician replaced the transmission valve body, did various software checks at the request of the factory. The engine control unit was then changed based on data supplied to the factory. At this point technician checked the car and dealers believes car is fixed. Vehicle has been returned to us on Nov 14 2024. We have requested the vehicle be bought back or replaced.
NHTSA ODI 11625278
Mar 1, 2024Electrical systemEngine
Check engine light appears, also a blue engine and a turtle. The dealer is aware, they have had it 3times for the same issue and this time 23 days and counting. Currently Mercedes has no fix. I purchased the veh 30 Nov 23- first appeared 16 dec and continued going on and off.
NHTSA ODI 11574918
Jan 19, 2024Engine
Brand new 2024 GLC300 4MATIC with less than 750 miles. Check Engine light came on with no error message explanation. Brought it in to dealer for service - Found fault code POA7F00. Dealer followed LI54.10-P-077250. Cleared codes. Check engine light is still on with no resolution to problem at this time. Was told to ignore and keep driving. Driving with check engine light illuminated is a safety concern for me.
NHTSA ODI 11566604
Jan 8, 2024Electrical systemLightsEngine
2 SEPERATE ISSUE DIGITAL LIGHTING FAILED, THEN 2ND ISSUE WHICH IS STILL BEING WORKED ON, BEEN A WEEK WITHOUT THE VEHICLE WHICH IS ONLY A MONTH OLD WITH 1100 MILES ON IT, THE ENTITE SYSTEM ISNT WORKING WITH LOTS OF CODE ERROR MESSAGES AND WILL NOT START. THE CURRENT UPDATE FROM MERCEDES IS THEY STARTED A CASE AND TESTING THE VEHICLE AFTER REPLACING THE POWER TRAIN. THE TECHNICIAN AGREED THIS IS NOT NORMAL FOR SUCH A BRAND NEW CAR. I AM CONCERNED FOR MY FAMILYS SAFETY AND THINK THIS IS A LEMON
NHTSA ODI 11564146