2024 Mercedes-Benz GLC 300 4MATIC

2. Service Department Misconduct —XXX Appointment On XXX, I brought my vehicle to the dealership’s service department for a pre-scheduled and confirmed appointment regarding a safety-related warning involving the emergency brake system. Despite having provided a full description of the issue at the time of booking, I was informed upon arrival that the diagnostic process would take more than five hours. When I asked about a loaner vehicle — standard practice at Mercedes-Benz dealerships in cases of extended service — I was refused, even though five courtesy vehicles were visibly parked on the lot and at least two other customers who arrived after me were provided loaners and expedited service that same day. I was made to wait in the lobby for the entire day. At approximately 5:00 p.m., just before closing, and despite no diagnostic work having been performed on my vehicle, a loaner vehicle was suddenly made available to me. This inconsistent and apparently discriminatory treatment in the allocation of loaner vehicles and service priority is unacceptable and warrants review. 3. Lack of Communication and Missing Documentation Following Service The technician assigned to my vehicle, [XXX], told me he would call me on Monday, XXX, once diagnostics were complete. He did not call. Instead, I received only an automated text message on Tuesday, XXX, stating the vehicle was ready — with no phone call, no email, and no explanation or summary of the work performed, contrary to standard practice at other Mercedes-Benz dealerships I have used. When I called to follow up, the technician did not answer despite multiple voicemails. I called the service department directly and asked for a supervisor; none was made available. After approximately one hour of calling the main dealership line, a sales associate attempted to reach the service department on my behalf and also received no answer. I then reached the technician directly. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11759873

Incident

Jul 20, 2026

The vehicle presented multiple warnings/errors before shutting down on the street in traffic on June 23, 2026. Warnings such as Collision Detected, Blind Spot Assist and Exit Warning Inoperative, PRE-SAFE Inoperative, System Failure Detected, Service Required Do Not Shift Gear, along with various lights on the dashboard which includes the Check Engine Light. The vehicle was towed to local Mercedes Benz dealership which reported the issue was with a drive train module that required a software update, the update was performed and vehicle was returned to me on June 25, 2026. On June 28, 2026 the warnings Blind Spot Assist and Exit Warning Inoperative, and PRE-SAFE Inoperative messages returned. Then on July 13, 2026 the vehicle shut down completely again in the same manner and error messages as initially reported. The vehicle was then towed to another dealership who reported seeing the same error messages, however they have not been able to replicate the issue after resetting the software.

NHTSA ID

11751243

Incident

Jul 13, 2026

The rear lift gate closes unexpectedly when standing behind the vehicle and loading or unloading the cargo area. The keyless soft close activates even though there is no foot movement, or when there is minimal movement. This happens without warning. On several occasions this has happened to me, and also to my wife. It has caused minor bruises, but more importantly we are both older and it has been difficult extricating ourselves and reaching the control to raise the gate again. While there have been no falls yet, it's only a matter of time before someone loses their balance or is hurt in some other way. This has been reviewed by the local dealer's service department who says there is nothing wrong. It has also been discussed with an engineer at Mercedes with no result.

NHTSA ID

11749171

Incident

Jul 7, 2026

Check engine light (MIL) came on while driving and vehicle lost power. Would not accelerate. Had it towed to Mercedes Benz of Mrytle Beach. $8000 repair. Mercedes Corp would not help. This is a copy of a TSB (LI05.20-P-080257) for this issue: Complaint engine vibrations perceived at low rpm. Fault codes for the camshaft position of the intake camshaft (p001100, p001104, p001200) or exhaust camshaft (p001400, p001404, p001500) may be stored. Cause continuously fluctuating oil pressure in the central valve may lead to damage to the filter screen on the central valve. This can result in damage to the filter screen or the filter screen breaking loose. The resulting loss of oil pressure prevents proper adjustment of the camshaft adjuster. If the filter screen breaks loose, parts of it may settle in the camshaft adjuster or in the camshaft. If there are parts in the camshaft, they can pass through the oil supply bore to the last camshaft bearing (i.E., the first camshaft bearing behind the adjuster) and cause damage there. Remedy 1. In cases in which only the screen of the central valve is damaged and no metal particles are found in the oil filter, the following parts must be replaced: - always both central valves - the camshaft adjuster of the damaged central valve 2. In cases where the screen is completely missing and metal particles are found in the oil filter, the camshaft bearings must be checked. If any damage is visible there, proceed as follows: - both central valves - the camshaft adjuster of the damaged central valve - the camshaft bearing housing (camshafts are already included here) - oil change with oil filter

NHTSA ID

11741971

Incident

Apr 25, 2026

My 2024 Mercedes-Benz GLC 300 has experienced multiple serious safety-related malfunctions involving several vehicle systems. In August, after picking up the vehicle from service, I placed my [XXX] grandson in his car seat, set my purse with the key inside the vehicle, and closed the rear door. The vehicle immediately locked all doors on its own, trapping my grandson inside in approximately 88-degree temperatures. I was unable to gain access for about 30 minutes. This created a dangerous child safety situation. Key fob periodically will lock you out of car. The following day, while driving approximately 35 mph with my [XXX] grandson in the vehicle, the car suddenly and violently applied the brakes and tightened the seatbelt without warning or any obstacle present. The vehicle came to a complete stop in the roadway. I later experienced bruising and increased neck pain afterward. I have also experienced repeated power liftgate malfunctions. While loading groceries, the liftgate failed to recognize my presence and closed on me unexpectedly, striking my head. The vehicle was brought in for service in November regarding this issue. Additionally, while driving on the highway, both side mirrors have suddenly folded inward without warning on several occasions, causing immediate loss of visibility and creating a serious driving hazard. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11736573

Incident

Aug 28, 2025

The contact owns a 2024 Mercedes-Benz GLC 300. The contact stated that while driving at approximately 35 MPH, the brake was applied unexpectedly without the contact depressing the brake pedal. The contact stated that she was unsure if the forward collision system was turned on at that time. The driver's seat belt tightened, and she sustained a bruise on her left arm and soreness on her chest. Medical attention was required. The vehicle was taken to a dealer where they were not able to replicate the failure. On another occasion, while parked, the tailgate was opened as groceries were being loaded into the rear cargo area. The tailgate closed inadvertently and struck the contact's head. The contact sustained head and neck injuries, and medical attention was required. The vehicle was taken to a dealer where the failure was not able to be replicated. The manufacturer was notified of both failures and advised that the automatic tailgate closing feature could be removed from the vehicle. The failure mileage was 31,153

NHTSA ID

11735615

Incident

Aug 22, 2024

Mileage

31,153 mi

New car was purchased from Rocklin Mercedes in California. Soon after the rear back up camera kept opening and closing when the car was in drive and at random times. The was then taken into Autobahn Motors in Belmont California to have the problem checked. I was told Mercedes was working on a software fix at which time the service tech never wrote up the problem. In 2025 the car again was taken into Mercedes for service at which time I brought up the same issue and was told most newer cars have this problem and there is NO fix, even the loaner they gave me had the same problem.

NHTSA ID

11716659

Incident

Sep 1, 2024

While carrying my carbon fiber bicycle on a rear hitch mounted bicycle carrier, the vehicle severely and violently applies the brakes and swerves either left or right or both. This catastrophic maneuver has put me and other drivers in a non avoidable highly calamity. This “AUTO” maneuver happens dozens of times in during a fifteen mile trip to local bicycle trails. Dealer replaced the Trailer Recognition Module 9-24-2025. As expected, dangerous situation remains. Happens every opportunity when carrying bicycles. First exhibited after purchase 6-29-2024 to current.

NHTSA ID

11690219

Incident

Sep 28, 2025

Issue Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, is launching an OTA update to the subject vehicles to provide an enhanced user experience. This OTA update includes enhancements to the MBUX voice assistant. Remedy MBUSA will conduct an OTA service campaign. Remote software updates are automatically downloaded and installed in the customer’s vehicle free of charge and do not require a dealer visit.

Complaint Diverse functional limitations in the vehicle in combination with various warning and fault messages in the instrument cluster display. Cause Communication timeouts mean that communication errors may occur in the on‑board electrical system, which can result in various fault messages being displayed in the instrument cluster. This could be down to delayed feedback from the drivetrain control unit (N127) (CPC) to other control units networked to the CAN bus. Information: Only valid for vehicles through production period 10/2025. Not valid for vehicles with control unit CDCC (N125, central controller charging and driving) • It may not be possible to attribute any communication errors stored in the control units on the CAN bus to a specific cause • In rare instances, there may be a brief activation of the yellow warning lamp for engine diagnosis or there may be a sporadic delay with the start enable. • There may not be any specific fault codes present that indicate a specific component. Example image: Fault messages in instrument cluster: The reason for this could be down to delayed feedback from the control unit CPC3 to other control units networked on the CAN bus. Remedy Do not replace any components!!! ******************************************************************************************************* 1. Connect charger (see AR54.10‑P‑1127WT). Note: An adequate voltage from the on‑board electrical system battery must be guaranteed for the entire duration of the work procedure. Otherwise, the control units could be damaged if an undervoltage occurs. Information: Observe the operating instructions of the charger. Information: Use the charger to ensure an adequate voltage (at least 12.5 V) from the on‑board electrical system battery. ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ 2. Connect diagnostic system (see AD00.00‑P‑2000‑06FR). Note: Always use the latest XENTRY Diagnostics software release. Information: Strict compliance with the operation steps in XENTRY Diagnostics is absolutely essential. ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ 3. Select control unit N127 (CPC) via the direct link using XENTRY Diagnosis. Information: To do so, select the following menu items: Control units view → Drive systems → N127 ‑ "Drivetrain" control unit (CPC) ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ 4. Update software for control unit N127 (CPC) (see AR54.21‑P‑0014‑01Y). Info: To do so, select the following menu items: Adaptations → Control unit update → Update control unit software. Information: You are then automatically guided through the steps "Update of control unit software" and "SCN coding". Always observe the following operation steps at all times ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ 5. Disconnect diagnostic device from vehicle (see AD00.00‑P‑2000‑06FR). ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ 6. Disconnect charger from vehicle (see AR54.10‑P‑1127WT).

Complaint Wheezing noises/squeaking noises from the front shock absorbers when passing over surface undulations and rough road. Noise MUST match those heard in the attached videos. Cause • Wheezing noises: Flow noises of the damper oil • Squeaking noises: From the mechanical rubber valve in the dividing piston Remedy In case of complaints, the front shock absorbers must be replaced. If shocks have been replaced and noise persists, please open a TIPS case to the Body, Chassis, Entertainment inbox.

Complaint Wheezing noises/squeaking noises from the front shock absorbers when passing over surface undulations and rough road. Noise MUST match those heard in the attached videos. Cause • Wheezing noises: Flow noises of the damper oil • Squeaking noises: From the mechanical rubber valve in the dividing piston Remedy In case of complaints, the front shock absorbers must be replaced. If shocks have been replaced and noise persists, please open a TIPS case to the Body, Chassis, Entertainment inbox.

Complaint Oil seeping from turbocharger oil return line at connection to engine block. Low oil level warning. Oil observed under vehicle. Cause Return line under tension due to turbo rotation. Remedy Inspect turbocharger housing for rotation (refer to attachment). If rotation is confirmed, the turbocharger and oil return line must be replaced.‑Resealing or replacing only the oil return line is not sufficient and will not resolve the symptom.‑Clean noise insulation on right side of engine if necessary. Replace insulation if cleaning is not sufficient.‑Observe foot notes regarding additional parts in XENTRY parts information when ordering turbocharger.

Issue A software update will be performed that provides enhancements to the robustness and system stability of the communication module. The update is free of charge and runs in the background, which takes about 8 minutes to install. During this time, the vehicle can be driven without any restrictions, and the new software will be active with the next ignition cycle. Remedy MBUSA will conduct an OTA service campaign. Remote software updates are automatically downloaded and installed in the customer’s vehicle free of charge and do not require a dealer visit.