2021 Mercedes-Benz AMG GLC43

Moisture began collecting inside the left headlight assembly, even though the housing should be sealed. Over time, the condensation increased and the front left turn signal failed. The vehicle displayed warning messages for the turn signal, low beams, Blind Spot Assist, Traffic Sign Assist, and Active Brake Assist. The failed turn signal reduces the vehicle's visibility to other drivers and creates a potential safety hazard. A similar moisture intrusion issue was the subject of NHTSA Recall 22V-261 for certain 2021 Mercedes-Benz GLC vehicles, but this vehicle was not included in that recall despite exhibiting the same symptoms. The vehicle is available for inspection.

NHTSA ID

11754832

Incident

Jul 21, 2026

The engine-driven vacuum pump and turbocharger boost-control vacuum system malfunctioned. The vehicle developed insufficient vacuum to the boost-control system, resulting in a P0299 turbocharger underboost fault and reduced engine power. The vehicle is available for inspection upon request. The vehicle experienced a noticeable loss of peak power and reduced acceleration. Although it did not enter limp mode, unexpected reduced acceleration could create a safety risk while merging onto a highway, passing another vehicle, entering or crossing traffic, or attempting to avoid a collision. An authorized Mercedes-Benz dealership scanned the vehicle, confirmed fault code P0299, and documented that vacuum supplied to the turbocharger boost-control system was too low. The dealership recommended replacing the vacuum pump and retesting the vehicle. The vehicle was inspected and diagnosed by an authorized Mercedes-Benz dealership. Mercedes-Benz USA reviewed the case and the dealership’s diagnosis as part of a goodwill-assistance request, but Mercedes-Benz USA did not physically inspect the vehicle. The vehicle has not been inspected by police or insurance representatives. The check-engine light illuminated, and the vehicle stored a P0299 turbocharger underboost fault. I also noticed reduced peak engine power and weaker acceleration. The vehicle did not enter limp mode. These symptoms first appeared at approximately 42,000 miles on or around June of 2026. Mercedes-Benz has issued an extended warranty for vacuum-pump failures on certain M157-powered vehicles that identifies the same vacuum-pump part number used in my M276-powered GLC 43 and describes similar symptoms, including low boost, a check-engine light, and P0299. Although my vehicle is not currently included in that extension, the use of the identical component and substantially similar failure raises concern that the affected population may extend beyond the listed M157 models.

NHTSA ID

11747935

Incident

Jun 10, 2026

At just 30,000 miles — less than half the mileage at which these failures are typically reported — my GLC 43 was found to have active oil leaks in multiple locations: 1. Front engine covers — oil is seeping from both the front cover gasket area and migrating downward along the engine block. The dealer recommends a full reseal of the front covers at a quoted cost of $1,944. 2. Radial shaft sealing ring of the front axle gear — is actively seeping gear oil, with a quoted repair cost of $1,718. My concern is not limited to cost. Oil migrating from the front cover area toward the lower engine, accessory belt, and turbocharger assembly creates a documented fire risk. The turbocharged M276 engine operates at extremely high surface temperatures in the areas where this oil is accumulating. I will be candid: I have genuine concern about operating this vehicle until these repairs are completed, and I am troubled that a safety-relevant failure of this nature is occurring at such low mileage on a vehicle in this price class.

NHTSA ID

11742742

Incident

Apr 6, 2026

2021 Mercedes GLC 43 headlight is inoperable. Same as reported in campaign 22V261000: "Headlight failure can decrease visibility for both the driver and surrounding traffic, increasing the risk of a crash." Although our car was produced before the dates reported in campaign 22V261000, I believe this is the same defect and the recall should apply to all MY 2021 cars as this is a serious safety issue. The dealer will not repair under warranty.

NHTSA ID

11689974

Incident

Sep 25, 2025

Panoramic sunroof exploded while driving.

NHTSA ID

11521032

Incident

May 8, 2023

The contact owns a 2021 Mercedes-Benz GLC43 equipped with Continental Tires, Tire Line: Sport Contact, Tire Size: 255/40/ZR21, DOT Number: AFHDD76M. The contact stated that on several occasions while driving at approximately 30 MPH and at low speeds on wet pavement, the vehicle started to shake, and a loud abnormal noise was heard in all four tires. No warning light was illuminated. The vehicle was taken to the dealer where it was diagnosed that the tires needed to be replaced; however, tires were not replaced. The manufacturer was notified of the failure and the contact was advised to call the NHTSA Hotline. The failure mileage was approximately 10,000.

NHTSA ID

11504702

Incident

Mar 31, 2022

Mileage

10,000 mi

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 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.

Dear Mercedes-Benz Owner: In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA is extending the warranty coverage for the Diagnostic Module for Tank Leakage Detection ("DMTL") on your vehicle from the original New Vehicle Limited Warranty of 4 years / 50,000 miles to 15 years/150,000 miles (whichever occurs first). This applies to the vehicle regardless of ownership. Why the Warranty extension? On certain Model Year 2018 - 2024 A / C / CLA / CLS / E / G / GLA / GLB / GLC / GLE / GLS / GT / S / SL Mercedes-Benz vehicles, under certain circumstances, the DMTL may trigger erroneous Diagnostic Trouble Code ("DTC") entries that may result in the illumination of the Check Engine Malfunction Indicator Lamp ("MIL"). Any repairs under this warranty extension must be performed by an authorized Mercedes-Benz dealership. • If your preferred authorized Mercedes-Benz dealership performs a diagnosis and confirms that your vehicle has the issue, the repair will be covered under this extended warranty and performed at no cost to you. • This extended warranty does not apply to any other components or conditions beyond the ones mentioned above, and standard warranty terms apply, including the exclusions with respect to extra expenses, as identified in the Service and Warranty Information booklet.

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.

Complaint A popup is seen on the HU with the message "data connection temporarily not available". Potentially affected functionalities in NTG4.5, NTG5 1.Weather 2.Local Search 3.IP Radio 4.Send2Car 5.Speech Detection Service 6.Navigation 7.iHeartRadio 8.Traffic Cams Cause MB Apps is sundowned for all vehicles with NTG4.5 and NTG5 Head Unit Variant. Remedy No support available for NTG4.5 and NTG5 Head Unit Variants for MB App related topics. Note: Please do not create TIPS. Please do not replace any components. HU/Hermes SW update / SCN coding will not fix the issue.

Complaint Clanking noise from the area of the speakers in the doors. Cause Under analysis. Remedy To narrow down the cause, first of all remove the door trim. • If the noise continues to occur even with the door trim removed, then continue the diagnosis working towards the speaker and if necessary, create a TIPS case with an informative video as an attachment. Information: Please refer to this document in the warranty claim and, after completing diagnosis, select the damage code corresponding to the component part that caused the problem. • If the noise stops when the door trim is removed, please proceed in accordance with LI72.10-P-067691. Information: In this case, do not use a damage code for the speakers in the warranty claim!