Problems owners report
Complaints filed with NHTSA about the 2018 Mercedes-Benz C 300 4MATIC, by the system named in each complaint. One complaint can name several.
- Structure4
- Unknown or other3
- Engine2
- Communication1
- Seat belts1
- Suspension1
- Air bags1
- Electrical system1
- Steering1
- Visibility/wiper1
NHTSA ODI complaints (public domain) · updated 23 Oct 2026 · 0 injuries and 0 deaths reported
Compared with other years
2018
NHTSA ODI complaints by model year
Fuel consumption
Official Canadian test results for 4 variants: combined 9.1–9.6 L/100 km (about 25–26 mpg US), CO₂ 214–224 g/km.
| Variant | City | Highway | Combined |
|---|---|---|---|
| C 300 4MATIC · Compact · Premium gasoline | 10.5 | 7.5 | 9.1 |
| C 300 4MATIC Coupe · Subcompact · Premium gasoline | 10.5 | 7.8 | 9.3 |
| C 300 4MATIC Wagon · Station wagon: Mid-size · Premium gasoline | 10.7 | 8.0 | 9.5 |
| C 300 4MATIC Cabriolet · Subcompact · Premium gasoline | 10.8 | 8.0 | 9.6 |
Litres per 100 km. Natural Resources Canada, Fuel consumption ratings (open.canada.ca) · Open Government Licence – Canada
Recalls
18V906000 · Exterior lighting19 Dec 2018 · 2,364 vehicles
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2018 Mercedes-Benz C300 and C300 4MATIC vehicles. The headlights on these vehicles may not be properly adjusted. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 108, "Lamps, Reflective Devices, and Associated Equipment."
18V838000 · Air bags27 Nov 2018 · 104,663 vehicles
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2018 C300 Cabriolet, C300 Coupe, C300 4Matic Cabriolet, C300, C300 4Matic Coupe, C300 4Matic, C43 AMG Cabriolet, C43 AMG Coupe, C63 S AMG Cabriolet, C350e Plug-In Hybrid, C63 AMG Cabriolet, C63 AMG Coupe, C63 S AMG Coupe, C63 AMG, C63 S AMG, 2018-2019 GLC300 4Matic Coupe, GLC300, GLC63 AMG Coupe, GLC300 4Matic, GLC350e Plug-In Hybrid, GLC43 AMG Coupe, GLC43 AMG, GLC63 S AMG Coupe, and GLC63 AMG vehicles equipped with Audio 20 head units and automatic child seat recognition. The status of the passenger side air bag may not display correctly.
18V608000 · Visibility11 Sept 2018 · 387 vehicles
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2018 Mercedes-Benz C300, C300 4MATIC, C63 AMG, and C63S AMG vehicles. Incorrect bonding of the rear window may cause the window to loosen and detach from the vehicle.
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 C 300 4MATIC: 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 |
| 11010755 | Complaint After a control unit replacement of "N112/9 - control unit for telematics services (HERMES)" or the "N112/2 - control unit for telematics services (RAMSES)", the Digital Extras (previously Mercedes me) cannot be activated. The DTC B15CE00 is active or active+saved. In vehicles with "N112/9 - control unit for telematics services (HERMES)": The message "SOS - service not activated" permanently lights up in the instrument cluster AND the actual value "Error when replacing certificate (CEP.36)" is displayed in the actual values for the activation status under "Registration status" (see |
| 11010494 | 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 |
| 11010455 | Complaint Only vehicles with a variable transfer case are affected. Can be identified through control unit N45 or N15/7 in the quick test When accelerating with light load, vibrations or jolting sensation may come from the drivetrain Cause Modified oil quality of the transfer case over time Remedy Check initial quick test for faults in the following control units N45 - All-wheel drive (ARS) N127 - 'Drivetrain' (PTCU) control unit Y3/8 - Transmission control for 9-gear transmission (VGS) N3/10 - Engine electronics for combustion engine If faults are present, process them as per the guided test |
| 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 |
| 11008880 | Complaint After a control unit replacement of "N112/9 - control unit for telematics services (HERMES)" or the "N112/2 - control unit for telematics services (RAMSES)", the Digital Extras (previously Mercedes me) cannot be activated. The DTC B15CE00 is active or active+saved. In vehicles with "N112/9 - control unit for telematics services (HERMES)": The message "SOS - service not activated" permanently lights up in the instrument cluster AND the actual value "Error when replacing certificate (CEP.36)" is displayed in the actual values for the activation status under "Registration status" (see |
| 11008873 | Complaint Tension-releasing impact of the propeller shaft with the force-free in D "KID" function, after vehicle has stopped. Cause The tension-releasing jolt in the drivetrain originates as a result of the "release" of energy stored when braking through the force-free switch after stopping. It is suspected that the longitudinal bearing is being placed under tension here as a result of the vehicle "dropping off". Remedy 1. Mark the installation position of the joint prior to the removal (picture a+b). This is important for vehicles with a weighted drivetrain ex factory to ensure correct instal |
| 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 |
| 11008323 | Complaint Headlamps fogged or droplets forming. Cause Due to its outlet openings, the headlamp is an "open system". This means that acidic gases, moisture, dirt and exhaust gases can penetrate into the headlamp. This can lead to the formation of condensation on the lens of the headlamp. The headlamps comply with all applicable US standards and regulations. Remedy Check housing cover of lamp unit for natural fogging or condensation as per LI82.10-P-078301. If a reduction in the degree of fogging is visible, the desiccant packs can be used once the condensation has completely evaporated. Note: O |
| 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. |
| 11008056 | Complaint Check engine light on. Fault code P207273 - "Throttle actuator valve is blocked due to ice" stored. Engine may crank and not start. Fault code P210185 may also be stored. Cause Moisture freezing on throttle actuator during extreme low ambient temperatures. Remedy Update software of engine control module. Software increases throttle valve flapping after engine turned off to prevent moisture buildup. |
| 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 |
| 11007728 | Complaint To insure vehicle down time is kept at a minimum and all required information is available when case is escalated, as well as assist technicians with checks that may help lead in resolving issue without case creation. THIS LI IS NOT TO BE USED AS A REASON FOR CASE CREATION BUT AS A GUIDE IF A CASE IS NEEDED Cause There are, at times, additional steps workshops can do to help diagnose and rectify transmission complaints. Remedy When opening a case for transmissions a EEPROM, Quick Test, and VGS CUL are absolutely necessary Please also check for any relevant LIs before opening case. Al |
| 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 |
| 11005344 | Complaint Customer complaints relating to automatic transmission 725.0 (NAG3 Classic / 9G-TRONIC automatic transmission) and 725.1 (NAG3 facelift/9G-TRONIC automatic transmission facelift) For faster, more effective and more targeted diagnosis, Intelligent Predictive Repair (IPR) has been developed and integrated into XENTRY Diagnosis. This ensures an automated diagnosis process. Cause As part of the on-going quality monitoring process and associated quality and damaged part appraisals, a high number of ineffective repairs have been discovered. Such ineffective repairs have a negative impact o |
| 11005331 | Complaint Only vehicles with a variable transfer case are affected. Can be identified through control unit N45 or N15/7 in the quick test When accelerating with light load, vibrations or jolting sensation may come from the drivetrain Cause Modified oil quality of the transfer case over time Remedy Check initial quick test for faults in the following control units N45 - All-wheel drive (ARS) N127 - 'Drivetrain' (PTCU) control unit Y3/8 - Transmission control for 9-gear transmission (VGS) N3/10 - Engine electronics for combustion engine If faults are present, process them as per the guided test |
| 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 |
| 10253722 | Check engine light illuminated Fault code stored in N3/10 control unit- P052E71 Positive Crankcase Ventilation Regulator Valve Performance: The valve for crankcase ventilation has a malfunction The partial-load ventilation valve (a part of the intake line assembly) may not work as intended. Model year 2015-2018 Performed guided test for fault code P052E71. Replace intake line assembly if necessary per results of the guided test. This LI will be updated once the software solution is available for model year 2015-2018 vehicles. Model year 2019 Perform software update for N3/10 Engin |
| 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 |
| 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! |
| 10246281 | Fault code P06DA00 is found current or stored in engine control unit. Check engine light may be activated. Various causes Up to Model year 2018 Fault code P06DA00 can be disregarded if not activating the check engine light, unless otherwise specified in the guided test. The vehicle continues to operate as designed. Further causes should be investigated if complaint of check engine light is received. If fault code P06DA00 is activating the check engine light, update software of the ME control unit. No further repairs needed if the code no longer activates check engine light after 2 d |
| 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 |
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