Running the y3/8n4 on the net comes up with " Y3/8N4 FULLY INTEGRATED TRANSMISSION CONTROL. 7G Tronic "

A shop manual would be needed to determine how to troubleshoot. The trans computer is in the pan on these units and is tied to the vin number so you can't just swap parts. ( MB calls this a theft related part and you need to prove proof of ownership to purchase parts. )