Hello all. I have a 2003, E500. Irregardless of temperature setting(s), only getting cold, ambiant air into the car. I would like to diagnose the problem, but do not know how to access the error codes. I found a link, from another post, but the instructions will not work for me ( called for hitting rest and ec buttons at the same time, but I have no ec button ).
Does anybody know the sequence for my model?
Thanks.

 

you need the heater valve located under the wiper assembly, remove cowl and wiper assembly the you will see the valve. that is your fix