This page covers 6 recalls and 263 owner complaints for the 2012 Mercedes-Benz C300.
For the 2012 Mercedes-Benz C300, the dominant complaint pattern centers on structural corrosion underneath the vehicle. The most-reported structural concern involves the rear subframe and crossmember rusting through, in some cases to the point where the rear suspension separates from the car while driving. Owners describe losing rear-end stability when this happens, with the broken components reportedly contacting the fuel tank in some instances. Front subframe corrosion shows up in complaints as well, with owners noting that steering and wheel components attach directly to it, making deterioration a handling concern. The corrosion complaints stand out because owners frequently describe the rest of the undercarriage as clean, with the subframe appearing to be the isolated problem area. Airbag complaints lead the overall complaint count by a wide margin but are less specifically described in the available reports. The structural and suspension complaints, by contrast, consistently point to subframe rust and separation as the core issue owners are reporting.
263
Total Complaints
5
Crash-Related
4
Fire-Related
5
With Injuries
By System
The 2012 Mercedes-Benz C300 has 6 recalls, the most serious involving Takata-type airbag inflators that can rupture and send metal fragments into the cabin, posing a risk of serious injury or death.
The inflator recalls cover both the driver and passenger frontal airbags. On the passenger side, prior repair attempts may not have fully resolved the issue: certain vehicles that received a replacement front passenger airbag under an earlier recall may have had an incorrect part installed, which can fail to protect occupants in a crash. There is also a separate concern where the driver airbag can deploy without warning, raising the risk of injury and loss of vehicle control. Rounding out the list, a software issue in the airbag control system can prevent the airbags from deploying at all in a crash, leaving occupants without that protection.
At a glance
What can fail
An incorrect replacement front passenger air bag module may have been installed during a prior recall repair, potentially causing the air bag to malfunction in a crash.
What the fix does
Dealers will replace the passenger air bag module with the correct part at no cost to you.
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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 →
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The passenger front air bag inflator may explode due to propellant breaking down after prolonged exposure to high humidity, heat, and temperature changes.
What the fix does
Dealers will replace the passenger front air bag module at no cost.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The passenger front air bag inflator may explode during a crash. This can happen because the inflator's propellant degrades after prolonged exposure to humidity and temperature changes.
What the fix does
The dealer will replace the passenger front air bag module 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.
At a glance
What can fail
Control unit software may be incorrect, potentially preventing airbags from deploying properly during a crash.
What the fix does
Dealers will update the control unit software at no cost to restore proper airbag deployment function.
Summarized — see the official notice for exact wording, dates, and contacts.
At a glance
What can fail
The front passenger air bag inflator may rupture during deployment in a crash due to propellant breakdown from prolonged exposure to humidity and temperature changes.
What the fix does
Dealers will replace the front passenger air bag modules at no cost to you.
Summarized — see the official notice for exact wording, dates, and contacts.
