SL55/63/65/R230 AMG: ATF fill port question???


BUT - in investigating further, I find that behind the right (passenger side) cylinder head (between it and the firewall) there is another tube with a red cap on it that appears about the same diameter. It has a black cap with a red 'tab' on the side, and something like "for MB Technician Only" printed on the cap. This cap is probably an inch or two below the top of the valve cover.
I just want confirmation that after I drain the ATF from the pan, replace the filter and pan, that I FILL the transmission with the correct fluid through the tube by the intake manifold!!
Any clues about what the other 'tube' is for would be interesting to me!
THANKS for your help to a newby in regard to working on this great automobile.
Gary Knox


