Problems owners report
Complaints filed with NHTSA about the 2018 Mercedes-Benz GLC 350, by the system named in each complaint. One complaint can name several.
- Fuel/propulsion system1
- Engine1
NHTSA ODI complaints (public domain) · updated 23 Oct 2026 · 0 injuries and 0 deaths reported
Compared with other years
20182019
NHTSA ODI complaints by model year
Recalls
21V058000 · Electrical system5 Feb 2021 · 1,292,258 vehicles
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2016 - 2021 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, GT-Class, C-Class, E-Class, S-Class, CLS-Class, SL-Class, B-Class, GLB-Class, GLC-Class, and G-Class vehicles. Please refer to the Part 573 report for specific vehicle model details. The software design of the communication module may fail to communicate the correct vehicle location for the emergency call system (eCall) in the event of a crash.
Whether a recall was fixed on a particular car is known only to the manufacturer: check the VIN at nhtsa.gov/recalls.
NHTSA recalls · summaries in NHTSA's own words
Service bulletins
What Mercedes-Benz told its dealers about the 2018 Mercedes-Benz GLC 350: known faults, fixes and updates.
| Bulletin | Summary |
|---|---|
| 11010818 | Complaint Transmission control unit Y3/8n4 (fully integrated transmission control unit (VGS)) not listed in quick test and/or no communication possible with VGS. Cause Transmission control unit Y3/8n4 Remedy It is important that LI54.15-P-057373 is processed before replacing any component parts (transmission 722.9). After processing and complying with the above documents, perform a reset on the transmission control unit Y3/8n4 (VGS) (ignition reset), check that the transmission connector is seated correctly and inspect the PINs for concerns. If communication with the VGS cannot be established |
| 11009122 | Complaint Washer fluid system leaks Cause Various possible causes: 1. Washer fluid reservoir itself. 2. Seal on washer fluid pump/washer fluid reservoir. 3. Washer fluid pump. 3.1. Distributor housing leaks. 3.2. Pump fitting leaks. 3.3. Washer fluid hose cannot be snapped into place on pump fitting. 3.4. Washer fluid hose will not stay on pump fitting, although connector OK. 4. Washer fluid line. 4.1 Connector will not stay on pump fitting because it is broken. 4.2 Sealing ring in connector missing. 4.3 Sealing ring in connector fitted, but deformed and therefore leaks. 4.4 Damage to washer l |
| 11008712 | Complaint Check engine light on. One of the below fault codes is current in the engine control module (N3/10). P04DB29, P04DB31, P04DB79 Cause Open circuit or high resistance to crankcase vent line contact Remedy 1. Check the electrical connector for the relevant vent line contact switch noted below. Refer to attached photos of connection locations. 2. Ensure the bolted connection is secure and bolt can be torqued (9Nm). 3. Check continuity from vent line connection to ME control unit. Repair wire if damage is found. The circuit from ME provides 5V and is pulled to 0V when the ground connecti |
| 11008091 | Complaint During a phone call, the called party has difficulty understanding/cannot understand the driver, or interference/background noises are audible to the called party during a call. It becomes increasingly difficult to understand as the speed rises. Cause A. Seating of the microphones in the headliner. Side edges are covered by the textile cover (see picture "1") B. Assembly of microphones (B25/20 or B25/21) in the headliner. C. Dirt inside the microphone housing Remedy 1. Press finger on rear of microphone (on adhesive tape) 2. Remove microphone cap from the front 3. Eliminate protrudin |
| 11008064 | In our continuing efforts to ensure the proper performance and quality of your vehicle, we are writing to inform you that on certain Model Year 2011-2018 C-Class, E-Class, S-Class, G-Class, CL, CLS, ML, GL, GLE, GLS, GLC, SL, and AMG GT vehicles with 6 and 8 cylinder gasoline engines, the software of the engine control unit may not meet current specifications. Under certain conditions, the catalyst heating might not work. Therefore, an Emission Service Campaign is being conducted to remedy the situation. Our records indicate that your vehicle is included in the affected population of vehicles. |
| 11007974 | Complaint Headlamps leaking or fogged Cause The fogging of the headlamp is a natural phenomenon which can occur under certain climatic conditions. In contrast to a leaky headlamp, physical fogging does not result in a technical impairment of the headlamp. A leak test must be performed to determine if physical fogging exists or if the headlamp is leaky. Remedy In advance, observe LI82.10-P-078301 "Headlamps or Front Fog Lamps Leaking or Fogged". 1. Prepare headlamp/check for external damage: For headlamps with a closed system 1. Check the headlamps for any external damage and check also for cor |
| 11007753 | Complaint Headlamp or front fog lamp leaky or fogged Cause Fogging of the headlamps is a natural phenomenon, which can occur under certain climatic conditions. It does not lead to any technical impairment of the headlamp. Headlamps comply with all applicable standards. If a pressure compensation diaphragm is fitted in the housing cover, then the lamp unit is a "closed system". Remedy Headlamp: Remedy 1 Clearing fogged/condensed LED headlamps and LED rear lamps: 1. Drive vehicle into workshop (temperature higher than +18 C/+64.4 F) and connect the exhaust extraction. Note: Do not perform an eng |
| 11006658 | Mercedes-Benz AG ("MBAG"), the manufacturer of Mercedes-Benz vehicles, has determined that on certain Model Year (MY) C-Class, E-Class, S-Class, G-Class, CL, CLS, ML, GL, GLE, GLS, GLC, SL, and AMG GT (204, 205, 207, 212, 213, 217, 221, 222, 463, 216, 218, 166, 292, 253, 231, and 190 platforms) vehicles with 6 and 8 cylinder gasoline engines, the software of the engine control unit may not meet current specifications. Under certain conditions, the catalyst heating might not work. MBUSA will conduct an Emission Service Campaign. An authorized Mercedes-Benz dealer will update the engine control |
| 11005294 | Complaint Rear lamps fogged up/not leaktight. Cause Fogging of the rear lamps is a natural phenomenon, which can occur under certain climatic conditions. This does not lead to any technical impairment of the rear lamps. Remedy Rear lamp: Remedy 1: Clearing fogged/condensed rear lamps: 1. Drive the vehicle into the workshop (temperature higher than +18 C/+64.4 F) Note: Do not wash the vehicle or subject it to high-pressure cleaning before the defogging test. 2. Switch off the engine and connect battery support via a charger. 3. Open the trunk. 4. Switch on the exterior lighting. 5. Leave the ve |
| 11000598 | Complaint Noticeable vibrations at the steering wheel: At speeds between 40mph and 75mph On straight stretches of road and in long corners With driver assistance systems switched on Cause Control oscillations in the electric power steering. Remedy Perform software update of electric power steering (N68). Note: Please ensure newest Xentry release software is installed and all addons are updated. After the software update, teach in the steering limitations of the electric power steering again: 1. Start engine 2. Turn steering wheel all the way to the left and briefly hold at the steering limi |
| 10252835 | Always use the latest XENTRY Diagnosis software release with all available add-ons. Make sure to follow the operation steps exactly as described in XENTRY Diagnosis. Use a battery charger to ensure sufficient power supply of the vehicle on-board electrical system battery (greater than 12.5 V). If XENTRY Diagnosis is already connected to the vehicle, start with operation step 2. If two or more software updates or SCN codings are performed during one workshop visit, operation items 02-4762 and 02-5058 may be invoiced only once for each workshop order. Work procedure 1. Connect X |
| 10249726 | Mercedes-Benz AG (MBAG), the manufacturer of Mercedes-Benz, has determined that in certain MY 2017-2021 C-Class, CLA, CLS, E-Class, GLC, GLE, GLS, AMG GT, S-Class, SL, and SLC (205, 117, 257, 213/238, 253, 166/292, 190/290,217/222, 231, 172) vehicles, the software of the communication module does not correspond with the latest series production configuration. This free of charge update includes quality-enhancing optimizations for the communication module to improve the system stability and better availability of the Mercedes me services. The update is downloaded and installed in the background |
| 10249543 | In our continuing efforts to assure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA, LLC (MBUSA) is extending the warranty coverage for the pressure sensor in certain Model Year (MY) hybrid vehicles listed below from the original New Vehicle Limited Warranty of 4 years/50,000 miles to 15 years/150,000 miles, whichever occurs first, due to the following issue: The pressure sensor installed on the fuel tank or on the fuel filler neck might detect an electrical error as a result of contaminated fuel, which could cause the chec |
| 10248162 | Crease formation on genuine leather seat covers in vehicles with low mileage Objects left on the seats for extended periods of time (pressure marks). Objects wedged between the seat backrest and seat cushion (e.g. seat belt buckle). Light initial creases due to vehicle handling. Light creases in the outer covers originating from the production process (missing finish). Heat treatment of the seat covers using heat gun and plastic wedge. Be very careful to not overheat the seat material! |
| 10244837 | The "SOS nonfunctional" message appears sporadically in the instrument cluster of the vehicle. The fault code B129C00 is stored in the control unit log. The message occurs in particular after the vehicle has been non-operational for an extended period of time; the message then disappears of its own accord after a few minutes. No functional limitation to the emergency call system is to be expected. Software error in N112/9 control unit for telematics services (HERMES). Software update for control unit N112/9 - Control unit for telematics services (HERMES) to software release E522.8. If |
| 10243565 | In our continuing efforts to assure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA (MBUSA) is extending the coverage for the intake line assembly 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), and applies to the vehicle regardless of ownership. Why the warranty extension? On certain Model Year 2015 - 2020 C/E/GLC/SLC and SLK vehicles, under certain circumstances, the partial-load ventilation valve (a part of the intake line |
| 10241790 | The Mercedes me connect services cannot be activated. The remote status data does not update. Error in N112/9 - control unit for telematics services (HERMES). In the HERMES control unit log, under the "URL" tab, the value DEFAULT is stored for "atpServerUrl" and/or "rcsServerUrl". Please carry out a re-commissioning of the control unit N112/9 - Control unit for telematics services (HERMES), which includes both a software update as well as coding. The fault will be rectified by the newly included coding. As a result of the software update to the current software of the control unit N |
| 10241531 | In our continuing efforts to assure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA, LLC (MBUSA) is extending the warranty coverage on the intake line assembly in certain Model Year (MY) vehicles listed below from the original New Vehicle Limited Warranty of 4 years/50,000 miles to 15 years/150,000 miles (whichever occurs first) due to the following condition: Under certain circumstances, the partial-load ventilation valve (a part of the intake line assembly) may not work as intended,resulting in the illumination of the chec |
| 10241527 | Mercedes-Benz AG (MBAG), the manufacturer of Mercedes-Benz vehicles, has determined that on certain MY 2018-2023 C-Class, EQE, EQE SUV, EQS, EQS SUV, GLC, GLE and S-Class (206, 295, 294, 297, 296, 254, 167 and 223 platform) vehicles, the communication module software does not correspond with the latest series production configuration. The update is free of charge and will be carried out in the background. The installation will eliminate software errors for a better entertainment experience. The update will show after the ignition has been cycled. MBUSA will conduct an OTA service campaign. |
| 10238437 | Mercedes-Benz AG (MBAG), the manufacturer of Mercedes-Benz, has determined that on certain Model Year (MY) 2016 2021 C-Class (205 platform), E-Class (213 platform) and GLC (253 platform) vehicles, the air conditioning control unit software may not meet production specifications. There is a possibility that a stuck open thermostat may wrongly be detected causing the check engine Malfunction Indicator Lamp (MIL) to illuminate. MBUSA will conduct an Emission Service Campaign. An authorized Mercedes-Benz dealer will perform a software update to the air conditioning control unit on the affected |
| 10238424 | In the MBUX weather app, the temperature is displayed in the wrong unit (Fahrenheit instead of C, or vice versa). Temperature setting in Mmc mobile application settings incorrect Remedy Adjust the setting in the Mercedes me connect app via mobile phone (settings -> units) |
| 10231024 | Complaint - AIRMATIC fault message in instrument cluster - Compressor inoperative, 40A compressor fuse possibly triggered. - Vehicle level is not adjusted correctly, the vehicle possibly leans at an angle Cause Moisture in the compressor freezes at temperatures below zero and may block the compressor. As a result, the starting current when the compressor starts up is too high. Fuse is triggered Remedy Replace compressor, fuse, and relay. Update software and SCN coding. Please invoice the case using damage code 32671 73. Addition: Unscrew pressure line between compressor and valve b |
| 10227145 | Complaint Staining on door trim strips and top and bottom trim elements on rear side windows Cause Damage to protective coating (due to poor original optimization of coating) of door beltline trim strips, door upper trim strips and side window trim element. Remedy 1. Check if the complaint cannot be rectified by polishing the trim bars with the polish. 2. If the complaint cannot be rectified, replace the door beltline trim bars, door upper trim bars and rear side window with trim element with optimized protective coating. |
| 10227142 | Complaint 1. Vibrations noticeable at steering wheel when front axle is excited when driving at a speed between 65 km/h and 130 km/h over an obstacle. Driving over deeply recessed manhole covers Driving over cross joints Driving over extreme surface undulations 2. Permanent or long-lasting vibrations at specific speed or engine speed noticeable on steering wheel. Roadway surface excitations when DTR+Q is switched on Cause Control oscillations in the electric power steering |
| 10225820 | Complaint Staining on door trim strips and top and bottom trim elements on rear side windows Cause Damage to protective coating of door beltline trim strips, door upper trim strips and side window trim element due to strong alkaline detergent in car washes. Remedy 1. Check if the complaint cannot be rectified by polishing the trim bars with the polish. 2. If the complaint cannot be rectified, replace the door beltline trim bars, door upper trim bars and rear side window with trim element with optimized protective coating. |
NHTSA manufacturer communications (public domain)
NHTSA investigations
EA21002 · Air bags:frontal:driver side:inflator moduleopened 17 Sept 2021
Desiccated Air Bag Inflator Rupture
NHTSA Office of Defects Investigation