Roughly 218,000 Mercedes sedans will be probed by US regulators after complaints of rear turn signal and brake light failures.
The US National Highway Traffic Safety Administration (NHTSA) has opened a preliminary evaluation of the luxury C-Class cars from model years 2008 and 2009 after receiving 21 complaints from consumers in the USA.
A spokesman for Mercedes, a unit of Germany's Daimler AG, did not have an immediate comment.
The reports typically said the failure is with the lamp connector, with many indicating burnt or melted electrical components, according to NHTSA documents.
In multiple instances, consumers have reported smelling smoke and seeing burn marks in the trunks of the cars, with one reporting small flames emanating from the rear lamp connector, the NHTSA said.
A preliminary evaluation is the first step in a process that could lead to a recall should regulators determine that a safety issue needs to be addressed by a manufacturer.