2026 Mercedes-Benz GLC 300 4MATIC

The contact owns a 2026 Mercedes-Benz GLC 300 4MATIC. The contact stated that her instrumental panel was not working, which caused her to be unable to see the gas level, oil, thermostat, and any warning lights. The vehicle was taken to a dealer twice. The first occasion the vehicle's instrumental panel was repaired. The failure reoccurred. The vehicle went back a second time, but was not repaired. The manufacturer was notified of the failure. The failure mileage was 5,769.

NHTSA ID

11744725

Incident

May 1, 2026

Mileage

5,769 mi

I was parked for a few minutes and I suddenly noticed a strong oder coming into my vehicle. I could not pinpoint what the smell was, but I knew that whatever was coming into the SUV was not safe. My screen started flashing warnings "Service Required: Do Not Drive" “Do Not Shift Gears”. After the warning, white smoke started to roll out from under the hood and into the vehicle. I immediately ran back to get my baby out of her car seat and to safety. I was at my local YMCA and staff ran out to I assist me and had a fire extinguisher. YMCA called the police and fire department. Both were dispatched to the scene. I called my husband for help while we waited for police & fire to arrive. My husband popped the hood and we saw large blue flames coming out from the transmission or the engine and we notice that transmission fluid started to leak under the vehicle. My husband put the fire out with the fire extinguisher. A police report was made. I contacted the dealership immediately. I contacted my auto insurance agent the next morning. The fire dept. used heat guns to test the heat level in the engine area. Prior to this, I did not have any issues with the vehicle. I believe this to be some type of mechanical or electrical malfunction or failure, based on the white smoke and blue flames. My daughter and I were put at extreme safety risk. If my husband and the YMCA staff did not assist, I feel that we would have lost our lives. With the large amount of smoke rolling into the air, children entering & leaving the YMCA were exposed to smoke/oder. Police had the vehicle towed to a tow lot near by to await Mercedes to pick up the vehicle and tow it to the dealership that I got the car from, so that it can be inspected. That was on 06/01/26. It is now 06/11/26 and Mercedes has not picked up the vehicle from the tow lot as they had confirmed that would be taking care of it.

NHTSA ID

11743388

Incident

Jun 1, 2026

I bought a 2026 GLC300 4matic SUV a month ago. I am very disappointed and scared of serious bodily damage due to the trunk door closing by itself while my upper body is loading/unloading the trunk. My wife and I were hit on the shoulder, back, arms, or head over a dozen times for 1 month. We took the car to the dealership for the problem but did not hear back from them for 3 days. The loaner car the dealership provided which is also 2026 GLC300 SUV also closes on me in the trunk. When the trunk shuts by tself while part of my upper body is in the trunk, it is impossible for me to stop it. It requires the 2nd person to stop the trunk door by forcefully pushing up. If I am alone, I don't know what could happen to me when tailgate closes on me. I have never had this problem with my old 2018 GLC300 4matic SUV for 8 years that has been traded-in to purchase this 2026 GLC300 4matic SUV. It turned out that the same problem has been discussed in the Mercedes GLC Forum with 19 participants, as shown in the link below: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11736668

Incident

Apr 30, 2026

The breaks on these vehicles are extremely dangerous . Before I leased this vehicle test drove 3 vehicles. The salesman said the breaks will adjust as you drive. They have not. ITS all over the internet that this vehicle has very unresponsive breaks. It takes 75 precent of pressure pushing down on the break pad distance before the car breaks engage. I already almost had an accident as the distance it takes for the car to respond is a significant distance before the car comes to a full stop. I have brought back the car to my dealership three times expressing my displeasure and each time I m told there is nothing they can do unless a fix comes from the manufacture. They said I'm not the first to complain about these dangerous breaks. What will it take for Mercedes to address this issue before someone gets killed. I hope there is someone at the NHTSA that will take the initiative to contact Mercedes and get them to address this very unsafe defect on these model cars. I thank you in advance.

NHTSA ID

11733775

Incident

Apr 17, 2026

While at a stop with foot on brake, the vehicle surges forward powerfully making a loud noise despite having foot on brake. Forcefully pushing on brake pedal harder eventually stops the car. Most recent time the display screen showed "Transmission Deactivated". Dealership drove car once but did not perform service inspection. Dealership to pick up/tow vehicle for service inspection. This happened four times in the eight weeks since pick up of vehicle as brand new. This could have cause a crash or caused vehicle to strike an object or person. Vehicle accelerated on its own and was difficult to stop.

NHTSA ID

11711555

Incident

Jan 16, 2026

Backup camera keeps opening and closing constantly while driving in slow speeds. While driving, backup camera keeps opening and closing, creating a noise and distraction to the driver and might cause accidents. The issue has been confirmed by the Mercedes Benz dealership service manager, describing as a recurrent in specific models with no current action plan or solution on near future. The car and component has been checked by the manufacturer. There are no warning lamps or symptoms prior to the problem occurrence and appeared at the first couple of days driving the car out of the dealership.

NHTSA ID

11710801

Incident

Dec 3, 2025

Complaint During part of the steering movement, it feels heavier or more difficult to steer in the same spot every time. OR Rattling, humming, dry sliding/gravel noise from the electric steering system when steering (see attachment). Complaint does not impact the ability to safely steer or control the vehicle. Cause Ball screw drive (KGT) of electric steering damaged by: 1. External force due to: ‑ Hitting the curb/posts with the front wheels. ‑ Driving over obstacles (e.g. pothole/ threshold/ speed bump/ gully) at an inappropriate speed. 2. Corrosion/ water ingress through a damaged boot (see attachment). ‑ Cracks (1) ‑ High pressure cleaner (2) ‑ Animal bite (3) See various examples listed in the attachments for examples of outside influence. Remedy Remove boot clamps closest to steering gear housing on both left and right (as seen in "Steering Rack Boot Clamp Location"). Pull back boot and inspect for rust, broken end stops, water, or any other anomalies. Replace electric steering. Note: Steering gears replaced due to outside influence or damage must not be claimed under warranty!

Complaint Frequent rear view camera flap actuations and/or noise associated. NOTE: Rear view camera functions are NOT affected and still perform in accordance with regulatory requirements. Cause Calibration of the reversing camera is in progress. This is not a malfunction, but an intended system behavior. Remedy An optimization has been implemented to reduce the quantity of rearview camera flap actuations for calibration. Open an XSS case requesting addition of the option code "0O1" (Zero, "O", "1"). Once the code has been added, update and SCN code PARK (N62/*) control unit. Prior to releasing the vehicle, please verify the following: • Rear camera flap when calibrating after a key cycle bus sleep will stay open to 29 MPH and then close. Will re‑open, when calibrating, at 9 MPH.

Complaint Tailgate opens unintentionally. Cause Accidental or unnoticed activation of the button to open the tailgate on the vehicle key. EXAMPLE: when stored in trouser pocket, handbag etc. Remedy As of the 6th generation, the vehicle key can be recoded so that the tailgate no longer opens as a result of a long press on the button, but by double‑clicking on the button instead. This reduces the likelihood of the button being activated accidentally or unintentionally. The recoding can be carried out as follows: 1. Add SA Code O19 into VeDoc (O for Oscar, not "zero") • an XSS ticket may be necessary to add the SA code 2. Perform SCN coding of EIS N73 control unit 3. Deactivate the vehicle key (a successful deactivation is indicated by the LED lighting up 2x briefly and then 1x for a long period). 4. Place the vehicle key in the storage compartment on the key symbol and turn on the ignition. IMPORTANT: all other vehicle keys must be outside the recognition range of the vehicle when doing this! Perform steps 3 and 4 successively for all vehicle keys. Notes: 6th, 7th and 8th generation keys can be deactivated as follows: Up to modification year 22/1 by double clicking the "Lock button" As of modification year 22/1, by press and holding the “Lock button", then double‑click the “Unlock button" at the same time. On model series 167, the storage compartment with the key symbol is located in the armrest. The SCN coding from the EZS is only transferred correctly to the vehicle key under the following conditions: Only one vehicle key is located in the vehicle, this key has been deactivated and it is positioned on the marking in the storage compartment for the data transfer. The costs for this adaptation are to be borne by the customer. For the newer BR 174, 178, 244, 248, 520, and 540, a software update must be initiated, as there is no way to perform SCN coding.

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 Update head unit software to latest version and the re‑check function in the same location. If vehicle is still exhibiting one of the symptoms as described exactly as in the complaint section or as shown in the video attachments, open a TIPS case to the Body/Chassis/Entertainment inbox with the following: • Video of the concern. • Exact location (latitude and longitude is best)

Complaint The following most common complaints may be observed: • Brief connectivity interruptions when using Apple CarPlay over Wi-Fi • Audio cuts out • Device not recognized • No operation possible Cause There are multiple possible causes for an iPhone disconnecting from a vehicle’s head unit while using Apple CarPlay. These include hardware, software, and environmental factors: Environmental Interference External Sources: • Passing under toll bridges, driving near airports, or areas with heavy electronic interference (e.g., as described in LI82.85-P-076157) can cause connection drops. Cellular Networks: • Interference from nearby cell towers operating on similar frequencies (usually 2.4GHz or 5GHz) can disrupt the signal. Storage Location: • Keeping your phone in a handbag or surrounded by other objects inside the vehicle can create physical or electronic interference. Device and Software Issues Head Unit Software/Hardware: • Outdated firmware, bugs, or hardware faults in the vehicle’s head unit can prevent a stable connection. iPhone Software/Hardware: • Similar issues in the iPhone, including buggy iOS updates or hardware problems, may affect performance. Reset or Reboot:• Automatic rebooting or resetting of either the head unit or the iPhone will temporarily disrupt CarPlay. Connection and Settings Wired Connections: • Faulty Cable: A damaged or poor-quality USB cable can cause intermittent or total loss of connection. • USB Port Issues: Dust, debris, or physical damage in the USB port of either the head unit or the iPhone can also lead to disconnects. Wireless Connections: • Intermittent Bluetooth/Wi-Fi: Unstable wireless communication (Bluetooth/Wi-Fi) can frequently break the Car- Play connection. Power Management: • Battery Saver Mode: Enabling low power mode may restrict background processes, affecting CarPlay. • Vehicle’s Electrical System: Unstable power delivery from the car’s battery or electrical interruptions can cause the head unit to malfunction. Phone & App Configuration Phone Settings: • Incorrect or conflicting settings (especially Bluetooth or Wi-Fi) on your iPhone can interfere with the CarPlay link. • Third-Party Apps/Profiles: • Installed apps or configuration profiles may conflict with CarPlay’s operation. • Native apps are apple maps, apple music, audio books, apple news, podcasts, messages and phone. All other apps are considered third party apps. App Conflicts: • Running conflicting apps that require similar system resources as CarPlay can cause instability. Mobile Data Plan: • Streaming from online sources without sufficient mobile data can result in lost connectivity. Other Factors Heat & Overheating: • If either the phone or the head unit overheats, they may disable certain functions to prevent damage, leading to disconnection. User Actions: • Accidentally disconnecting the device in settings, or physically moving or bumping the phone or cable, may disrupt the connection. Remedy FUP6 (E605.8) software has been released for the following chassis: 118, 177, 243,247,206,254,167,294,295,296,223, 297. Flash available software for the head unit and test for function. The LI will be updated once available for the remaining chassis. If the complaint remains after the SW update please continue with the steps below. Guided Diagnostic Path for Apple CarPlay Connection Issues: Please follow the steps below to systematically diagnose and resolve CarPlay concerns:Update Devices: • Ensure the iPhone is updated to the latest available iOS version. • Ensure the vehicle’s head unit is updated to the latest software version available. Isolate the Issue: • Check whether the symptom persists with another iPhone running the latest iOS version. • Test both wireless and wired CarPlay connections: • Does the issue only occur with wireless CarPlay? • Does the wired connection to the phone function correctly? Further Troubleshooting Steps: • Reboot the iPhone. See attachment for further instructions.

Complaint 1. General Diagnostic Tips 2. One or More PARK Sensor Activations 3. Red Ring Around Vehicle 4. "Active Parking and Parking Assist Inoperative" on Instrument Cluster 5. Cameras 6. Other Park Topics. Cause Various root causes Remedy See attached diagnostic guide.