NHTSA (USA)High Risk
At a glance
This page covers 18 recalls and 96 owner complaints for the 2018 Mercedes-Benz C 300.
For the 2018 Mercedes-Benz C300, engine complaints make up the largest share of what owners report. The most common themes involve the check engine light illuminating alongside diagnostic codes, and in several cases owners describe complete engine failure at relatively low mileage, some reporting the engine cutting out at highway speeds. Steering complaints are the second most reported area, though the specific symptoms described vary across accounts. Structure complaints, many of which center on the panoramic roof, frequently involve water leaking into the cabin, with owners noting the glass moving or failing to seal properly during washing or rain. A smaller number of owners also report the backup camera displaying a black screen when the vehicle is shifted into reverse, and at least one report mentions a seat belt failing to retract after use.
96
Total Complaints
4
Crash-Related
1
With Injuries
By System
The 2018 Mercedes-Benz C300 has 18 recalls, the most serious involving a steering coupling that may not be fully locked, which can cause the mechanical connection between the steering wheel and the rack to come loose and reduce steering control.
A second steering recall covers the steering rack itself on rear-wheel-drive models, where wear or damage can make the car difficult to steer properly. On the structural side, the adhesive bonding on the front roof panel can deteriorate and allow the panel to detach as a road hazard; a prior repair attempt on some vehicles did not fully resolve this issue. The rear window can also loosen and detach, and on cabriolet models, the rear beltline trim can separate while driving.
Several recalls involve occupant safety. Front seatbacks may not lock properly on the right side and can fold forward in a crash. The driver airbag can inadvertently deploy, and the passenger seat sensor that controls airbag activation may incorrectly show the airbag as active when it is not. Front seatbelts on some vehicles may not fully retract, which can discourage use. In a crash, a poorly covered battery terminal can short-circuit and start a fire while also disabling emergency door unlocking, and a loose battery mounting bracket can allow the battery to disconnect or detach entirely.
Three separate recalls address the emergency call system, which can fail to connect, send responders to the wrong location, or stop working altogether. Headlights on some vehicles were set at incorrect angles, reducing nighttime visibility.
At a glance
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Complaints are owner-reported and reflect individual experiences, not confirmed defects. They are distinct from recalls. Data sourced from the national vehicle safety complaint database. See trending complaints →
What can fail
The front roof panel between the windshield and panoramic sunroof may have been improperly bonded during a prior repair, causing the panel to detach from the vehicle.
What the fix does
Dealers will replace the front roof panel at no charge to you.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
A software error in the communication module's SIM card can prevent mobile network connection, which disables the emergency call (eCall) system.
What the fix does
The communication module software will be updated at no cost through an over-the-air update or by a dealer.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
LED headlights may have been incorrectly adjusted during a repair, causing them to not meet federal lighting standards.
What the fix does
Dealers will replace the LED headlights at no cost to you.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The front roof panel between the windshield and panoramic sunroof may not be properly bonded to the vehicle from a previous repair, risking separation.
What the fix does
The dealer will remove and replace the front roof panel using proper bonding materials and procedures at no cost.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The communication module may have been turned off during service, disabling the Emergency Call function that connects your vehicle to emergency services.
What the fix does
Dealers will inspect the communication module and reactivate it if needed, at no cost to you.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The communication module software may fail to send your vehicle's correct location to emergency services when the eCall system activates during a crash.
What the fix does
A dealer will update the communication module software, or the update will be sent over-the-air, at no cost.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The front seat belts may not fully retract back into their stowed position after use.
What the fix does
Dealers will check the front seat belt retraction and adjust the damping foam in the B-pillars as needed at no cost.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The 12-volt battery mounting bracket may not be properly secured, allowing the battery to shift during a crash and potentially disconnect the terminals.
What the fix does
Dealers will replace the battery mounting bracket at no cost to you.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The right side of the front seat seatback may not lock securely in place.
What the fix does
Dealers will inspect the seatback lock and replace it if needed at no cost to you.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The headlights may not be properly adjusted, failing to meet federal lighting standards.
What the fix does
Dealers will inspect and adjust the headlights as needed at no cost.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The steering coupling may not be properly locked, which could allow it to move unexpectedly during driving.
What the fix does
Dealers will inspect the steering coupling and secure it correctly if needed at no cost.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
A locknut in the steering rack may break under heavy load, potentially causing the steering to lock in one position.
What the fix does
Dealers will replace the steering rack at no cost to you.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The passenger side air bag status may not display correctly on the instrument cluster in certain 2018-2019 C-Class and GLC-Class vehicles with Audio 20 head units.
What the fix does
Dealers will update the audio head unit software at no cost to correct the air bag status display.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The starter battery cover may not fully protect the live positive wire. In certain crashes, the strut brace can deform and short-circuit the battery.
What the fix does
Dealers will replace the positive pole cover at no cost to you.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The rear window may not be properly bonded to the vehicle, which can cause it to loosen and detach.
What the fix does
Dealers will rework the rear window bonding at no cost to restore a secure attachment.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
A bonding problem during manufacturing can cause the rear beltline trim to separate from the vehicle.
What the fix does
Dealers will inspect the rear beltline trim and replace it if needed at no cost.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The right seatback on front seats may fail to lock properly, potentially allowing the seat to move unexpectedly.
What the fix does
Dealers will inspect the front seatback locks and replace them if needed at no cost to you.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The driver's airbag may deploy unexpectedly if the steering components lack proper grounding and the airbag clockspring is broken, allowing electrostatic discharge to trigger deployment.
What the fix does
Dealers will add grounding to the steering components to prevent electrostatic discharge from triggering the airbag.
Summarized — see the official notice for exact wording, dates, and contacts.