UPDATE: Added details on the fix from Mercedes-Benz Canada.
Mercedes-Benz Canada is recalling 27,000 cars and crossovers to address a fire-prone fuse at the heart of a global campaign to fix one million vehicles.
According to Automotive News and Transport Canada, if the car doesn't start the first time, and the driver repeatedly attempts to start the engine, a fuse in the starter motor (called a current limiter) could overheat and melt nearby components.
The US National Highway Traffic Safety Administration (NHTSA) says Daimler (Benz's parent company) research showed that in 51 reported fires caused by the faulty fuse, the starter was "blocked," or unable to turn, because of prior engine or transmission damage, citing that as an "essential" pre-condition for the defect addressed by this recall. The NHTSA specifically mentions a hydro-locked engine as a possible cause, where the combustion chambers have become flooded with water (or fuel, we assume), "locking" the pistons in place.
Benz's fix for the affected models is to install an additional fuse to the starter's wiring to cut current before the existing fuse overheats. The recall affects most of Mercedes-Benz Canada's best-selling models, including the 2015 through 2017 Mercedes-Benz B-Class, 2015 through 2017 Mercedes-Benz C-Class, 2015 through 2017 Mercedes-Benz E-Class and 2015 through 2017 Mercedes-Benz CLA-Class cars, and 2015 through 2017 Mercedes-Benz GLA-Class and 2015 through 2017 Mercedes-Benz GLC-Class crossovers.
While they're busy fixing existing customers' cars, Mercedes-Benz in the US will reportedly stop selling those six models, a number of which are among the brand's best-sellers, putting a potential damper on sales during the profitable spring selling season. Mercedes-Benz Canada said the stop-sale applies here too, as they will fix all affected cars on dealer lots before selling them; the work will take about an hour to complete per vehicle.
"As our top priority is the safety of our customers, we will install an additional fuse in the electrical line to the starter, as a precautionary measure," said a Mercedes-Benz Canada statement. " This is expected to take approximately one hour to complete and will be performed free of charge. New vehicles will be fitted with this new fuse before they are sold."