where is the input shift speed sensor A circuit located?

Hello, You must inspect the 13 pin connector on the transmission for fluid. You can try cleaning both halves of the connector with electrical parts cleaner, but if there is transmission fluid, the connector and gaskets should be changed. Next, make sure that the transmission fluid is correct, and that you have no leaks. Next, if you did not change the filter, you have to go back in, and change it. This is a good thing since there were no drain plugs on these torque converters, so the old fluid has mixed with the new fluid to the tune of about 1:2. Changing it again will bring it to a nice 1:4 ratio. Next, go into the vehicle, drive like normal, and shift the vehicle manually through all available gears. If the problem is resolved, the transmission control unit will likely turn off limp mode. If you need further assistance, let me know, otherwise, here is a list of certified shops in your area that can diagnose and repair your vehicle: http://repairpal.com/mercedes-benz-within-10-miles-of-nowata-oklahoma-74048