First thing I always request is this. If there is a power interruption to a computer, and your car has no less than 12, then that could be a common denominator.
Anyway, where I am going is towards a body control module which controls all these functions but a scan tool is required to monitor commands and what is on and off. Your benz is a real complicated piece of equipment and without actually being able to monitor these systems, it would be an educated guess. These guesses get real pricy on your car as all module require programming after installation.
As far as a ground, start at the battery cables and clean all connections anywhere you find a ground.
Tuesday, February 19th, 2013 AT 11:39 AM