2025 Mercedes-Benz GLC 300 4MATIC

Vehicle experiences a severe, abrupt jerk/jolt during deceleration around the 5th-to-4th gear downshift. The issue occurs consistently when slowing down. Dealership verified the condition on Repair Order #1906625 and confirmed a transmission flaw. Dealer stated software is required from the manufacturer with no ETA for release. The abrupt deceleration creates unexpected cabin jolting during normal traffic slowing.

NHTSA ID

11755359

Incident

Jul 22, 2026

The instrument cluster display went dark and has not been able to display any information such as speed in miles per hour, fuel gauge, and other important information needed to maintain safe driving.

NHTSA ID

11742067

Incident

Jun 3, 2026

All of the screens in the car failed to start. They remained black while the car was running. Turning the car off did nothing. Drove to a parking lot, turned the car off, got out, locked the car, waited 5 minutes and it still didn't come back. Had to do a reboot by holding the system power button for 10 seconds. This has occurred 3x in 9,200 miles.

NHTSA ID

11729806

Incident

Mar 27, 2026

See attached document for complaint.

NHTSA ID

11723770

Incident

Jan 17, 2026

To the Office of Defects Investigation National Highway Traffic Safety Administration I am submitting this complaint to formally report a serious and recurring safety defect involving the automatic braking and collision detection systems in our Mercedes-Benz GLC. License Plate: 9RHN710 Dealer Servicing Vehicle: Mercedes-Benz of Stevens Creek (AutoNation), San Jose, California The vehicle has repeatedly experienced unexpected and unprovoked braking events, including situations where the automatic braking system engages despite there being no vehicles, pedestrians, or visible obstructions present. The issues observed include: • Sudden automatic braking activation without obstruction • Unexpected vehicle deceleration during normal driving conditions • Repeated dashboard alerts indicating “Speed Severely Restricted” • Repeated Attention Assist / “Coffee Break” warnings during normal local driving • Sudden brake engagement when parking, accompanied by a loud mechanical noise These events create a dangerous driving condition, as unexpected braking could lead to a rear-end collision from vehicles traveling behind the driver. During one incident, the abrupt braking caused a severe jolt to the driver, resulting in whiplash symptoms that required medical evaluation and MRI imaging, which identified cervical strain. The vehicle has been brought to the authorized dealership multiple times for inspection and repair attempts. However: • The dealership has not been able to diagnose or repair the issue • Service visits have largely been documented as general inspections • No ADAS (Advanced Driver Assistance Systems) diagnostic or calibration report has been provided, despite the fact that the malfunction appears directly related to radar, camera, or collision prevention systems. We respectfully request that the Office of Defects Investigation review this complaint and determine whether further investigation into this issue is warranted.

NHTSA ID

11723692

Incident

Mar 5, 2026

The component that repeatedly fails is the vehicle’s electronic display/infotainment system (dual digital screens/MBUX system) and potentially related electrical components in my 2025 Mercedes-Benz GLC 300 4MATIC. The system has malfunctioned six (6) separate times since I purchased the vehicle new in May 2025. When the malfunction occurs, both display screens suddenly go completely black and become inoperable while the vehicle is running. During these failures, the vehicle also produces a repetitive clicking sound from the dashboard area while the screens are off. The most serious incident occurred on February 17, 2026, when the screens shut down while I was driving and I detected a burning electrical smell inside the vehicle. This raised significant concerns about a possible electrical malfunction or fire risk. The digital display system provides critical driving information, including vehicle settings, safety alerts, and operational controls. When the screens shut down, the driver loses access to important vehicle information and control functions, which creates a potential safety hazard while operating the vehicle. This issue has been reproduced multiple times and the vehicle has been taken to Mercedes-Benz of Jackson, Mississippi for inspection and repair attempts on several occasions. The dealership has attempted repairs and indicated that they have opened a case with the Mercedes-Benz manufacturing department regarding the recurring electrical issue. Due to the repeated electrical failures, clicking sounds from the dashboard area, and the burning electrical odor detected while the vehicle was in operation, I am concerned that this issue may indicate a serious electrical defect that could potentially lead to overheating or fire. The malfunction occurs while the vehicle is being driven, which places the driver and passengers at risk. Because the display system repeatedly shuts down and the issue has occurred multiple times despite dealer inspections and repair

NHTSA ID

11721877

Incident

Feb 17, 2026

BOTH DASHBOARD SCREENS WENT DARK AND REMAINED SO THROUGH 5 CYCLES OF STARTING THE CAR. HAD NO OPERATING INFORMATION WHATSOEVER. TOLD BY DEALER THAT MANY 2025 GLC-300'S ARE EXPERIENCING THE SAME PROBLEM.

NHTSA ID

11706872

Incident

Nov 17, 2025

The instrument panel behind the steering wheel has gone totally dark. This issue happened about a month ago but resolved itself somehow. Issue happened again and will not correct itself. Took vehicle to dealer and they could not resolve issue with software update. Upon researching the MBWorld.org user forum I noticed this may be a wide spread issue. With a dark/blank instrument panel you cannot know your speed, fuel level, or what gear you have placed the car in. My technician even indicated he has seen this issue on several 2025 MB models.

NHTSA ID

11695851

Incident

Sep 24, 2025

Complaint After an "Over the Air" update (OTA), FM or SDARS radio reception is limited; only a few stations are found. Cause The firmware installation was incomplete. Remedy In the A26/17 control unit "MBUX multimedia system" (head unit), use XENTRY to carry out the special process "All Modules"; this will reinstall the firmware completely.

Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The noise is heard once in each instance when changing direction of travel. Note: Sound file in attachment Cause If the complaint is eliminated by experimentally loosening the outboard collar nut (by 1 turn), the problem is due to cracking of the microweld between the wheel bearing inner race and the joint housing of the side shaft. Note: The collar nut must always be replaced after being loosened. See also LI33.20-P-078406 Remedy Coat contact surface of side shaft with wheel bearing with Molykote paint. To do this, proceed as follows: 1. Remove side shafts 2. Clean contact surface A (see image file in attachment "Outer joint housing before") before coating with Molykote, using "spirit" (free of dust and grease) 3. Coat contact surface A (see image file in attachment "Outer joint housing after") with Molykote and leave to dry for "one hour" in removed condition 4. Reinstall side shafts Note: Before using the antifriction coating (Molykote), stir it or shake it thoroughly for (at least 1 minute).

Complaint Traffic sign symbol for "Traffic Sign Assist" is blinking in instrument cluster without obvious cause usually with one of the following scenarios: • Flashing without a speed limit ("- -"). • Flashing when current vehicle speed is under speed limit. • Flashing between US speed limit symbol and European speed limit symbol. NOTE: • Verify that the concern falls under one of the attachment videos. If not, then it is outside of the scope of this LI. • This also does not cover "Traffic Sign Inoperative" messages on the instrument cluster. Cause There are two identified reasons for this concern: 1. Country code information stored incorrectly at a particular geographic latitude range. 2. Incorrect reference data when the vehicle is started and a GPS signal is not immediately available. Remedy Do not replace parts. Please open a TIPS case to the Body/Chassis/Entertainment inbox but read the below carefully: • The vehicle must be exhibiting the concern as shown in the attachment videos. • The vehicle DOES NOT need to be at the dealer, nor does it need to be brought into the dealership. • If the geographic location is known, it is very important that it is provided. • Provide any pictures or videos, if available. A new software for the head unit is scheduled for tentative release in Q3 2026.

Complaint Creaking noise, in irregular sequence when driving slowly in combination with slight steering movements and/or Creaking/crackling noises from the area of the wheel bearing on the front axle when cornering/ maneuvering. Sound file attached for comparison. MUST match noise for proper diagnosis. NOTE: Steering functionality is not affected. Cause Contact area between wheel bearing and steering knuckle. See also: LI35.30-P-058566 (Throttle Lift-Off Noise - Rear) LI33.30-P-056665 (Throttle Lift-Off Noise - Front) LI40.10-P-059248 (Wheel cracking noise when cornering) Remedy 1. Perform Operation A and evaluate by testing vehicle. 2. If noise is still present after re-testing: • If 192/232 chassis, verify FIN is in the listed range below in "Operation B" and perform. • If not 192/232 chassis or vehicle is a 192/232 not in the listed FIN range, additional verifications of where the noise is coming from are needed. Use multiple channel NVH method to narrow down location. Verify the LI's listed above were completed or if there are other similar noises associated with the chassis (Example: 192/232 also has under panel noises and an associated LI). Operation A: 1. Clean contact surfaces of wheel bearing and steering knuckle with brake cleaner as seen in the attached pictures. NOTE: The front area of the wheel bearing and the seals must not come into contact with the cleaner, otherwise, the sealing rings will be damaged. 2. Clean threads of wheel bearing mounting. 3. Thinly coat contact surfaces of wheel bearing, steering knuckle, and axle mating face with Molykote (annular joint grease). See the attached steering knuckle and wheel hub pictures for reference. NOTE: Axle mating face greasing is also covered in LI35.30-P-058566 and LI33.30-P-056665. Operation B (Only applies to 192 and 232 in listed FIN range): Only affects vehicles up to FIN end number: • Model series 192: xxx xxx xx 002 876 • Model series 232: xxx xxx xx 022 312 1. Replace steering knuckle. 2. Wheel bearings do not need to be replaced.

Complaint Radio station cover art does not refresh when switching stations. The UI continues to show the old station’s artwork instead of updating to the new one. Cause When a new station change request is triggered, a temporary glitch is causing the Head Unit application to fail to overwrite the previous request. This glitch is causing the cover art mismatch in the Radio application. Remedy Please do not replace any parts. The E505.9 software is released and available in XENTRY Q3 2026.

Complaint Creaking noise, in irregular sequence when driving slowly in combination with slight steering movements and/or Creaking/crackling noises from the area of the wheel bearing on the front axle when cornering/ maneuvering. Sound file attached for comparison. MUST match noise for proper diagnosis. NOTE: Steering functionality is not affected. Cause Contact area between wheel bearing and steering knuckle. See also: LI35.30-P-058566 (Throttle Lift-Off Noise - Rear) LI33.30-P-056665 (Throttle Lift-Off Noise - Front) LI40.10-P-059248 (Wheel cracking noise when cornering) Remedy 1. Perform Operation A and evaluate by testing vehicle. 2. If noise is still present after re-testing: • If 192/232 chassis, verify FIN is in the listed range below in "Operation B" and perform. • If not 192/232 chassis or vehicle is a 192/232 not in the listed FIN range, additional verifications of where the noise is coming from are needed. Use multiple channel NVH method to narrow down location. Verify the LI's listed above were completed or if there are other similar noises associated with the chassis (Example: 192/232 also has under panel noises and an associated LI). Operation A: 1. Clean contact surfaces of wheel bearing and steering knuckle with brake cleaner (see areas marked blue in pictures "2.jpg" and "3.jpg"). NOTE: The front area of the wheel bearing and the seals must not come into contact with the cleaner, otherwise, the sealing rings will be damaged. 2. Clean threads of wheel bearing mounting. 3. Thinly coat contact surfaces of wheel bearing, steering knuckle, and axle mating face with Molykote (annular joint grease) (see areas marked blue in pictures "2.jpg" and "3.jpg"). NOTE: Axle mating face greasing is also covered in LI35.30-P-058566 and LI33.30-P-056665. Operation B (Only applies to 192 and 232 in listed FIN range): Only affects vehicles up to FIN end number: • Model series 192: xxx xxx xx 002 876 • Model series 232: xxx xxx xx 022 312 1. Replace steering knuckle. 2. Wheel bearings do not need to be replaced.