Mercedes-Benz is recalling certain model year 2013 SL-Class vehicles manufactured from 19 December 2011, through 31 May 2012 originally equipped with R-1234yf refrigerant. In September, Daimler, the parent company of Mercedes-Benz, announced that, based on internal safety testing, it would no longer use R-1234yf as a replacement refrigerant in mobile air conditioning (MAC) systems. (Earlier post.)
In the recall notice, Daimler noted that it had conducted product testing of a vehicle, not sold in the US, but equipped with the same refrigerant. According to Mercedes-Benz, the testing was designed to replicate worst-case conditions expected in a severe frontal crash that would cause a rupture of the air conditioner refrigerant line. A rupture of a refrigerant line will result in a gaseous mixture of refrigerant being released into the engine compartment.
The testing conducted by DAG determined that the escaping R-1234yf refrigerant may ignite under specific conditions. The resulting fire could spread to additional combustible materials.
Mercedes-Benz will replace the R-1234yf refrigerant with R-134a along with new refrigerant lines (hoses) designed specifically for R-134a. The remedy will be provided free of charge. The safety recall is expected to begin during October 2012.
R-1234yf has been widely accepted as a lower global warming potential replacement for R-134a in mobile air conditioning (MAC) systems.