Hi I'm new to the site but have had a few insights reading the threads. I have a 2008 E-350 amg package ( wife's car) worked great then suddenly won't start. Changed the cps and the relay for the fuel pump but still cranks and no strt. Does anyone know how to test the rear Sam before I replace and do you need to re program this? Any direction would help thanks all ill be posting a pic soon.

 

Take it to an indie shop that has proper equipment to connect to car's computer and find out what is wrong. You may have already spent more than a tow and scan would cost.