Water Leak Could Cause The Mercedes-Benz C-Class To Catch Fire

Of course, this is all supposing the short does occur. Across 6,700 cars, the odds are rather slim the C-Class in your driveway is the one. We did some digging, and it appears that the aforementioned signal acquisition and actuation module (SAM) is used to control any variety of actuators (like turn signals) in Mercedes models.

Other issues triggered by a shorted SAM include exterior light failure, unintentionally folding rear seatbacks, and failure of the rearview camera. Basically, anything that's under the control of this actuation module is prone to failure. It just depends on where and how the leaky water lands. Put another way, it's a crap shoot.

As with any other recall, from Mercedes or any other brand, owners of affected cars will be getting a warning in the mail. All cars involved were C300 models built between June 24, 2021 and May 13, 2022. Merc was initially made aware of the issue just after the 2022 model was introduced in the US. Filings say that was on May 6 of the same year.

However, if you're the owner of one of the unlucky cars, opening the trunk appears to be the issue, and not doing so while it's wet could stave off the problem. Merc found that opening the trunk while it's wet allows water to drip into the trunk. Much of this is likely run-off designed to flow down the trunk's seams, onto the lower bumper, and off the car.

From there, the water can seep into the SAM, frying (or maybe not frying) any electronics inside. Again, it's a total crap shoot which ones could be affected within the module. As of now, Merc knows of 42 warranty claims related to the issue. No injuries, crashes, or any other damage have been reported as a result of the fault.

If you own a C-Class, you'll be getting notice on or before November 11 this year. Should you draw the short straw, the nearest dealer will fit a cover to the SAM to keep water off it.