Audi Repair: 2000 audi a4 cranks but will not start, engine cranks, audi a4

Question
found fault code p1850, data bus powertrain missing from engine contr. how do i fix this? could this be the ecm. noticed, no check engine lite on the dash when ign sw turned on and during cranking. engine cranks but no start. thanks for your help.

Answer
It sounds like a connection between ECM and computer, perhaps a bad connection or corrosion on terminals.  I would check the connectors first.  Since the computer is not getting any signals like crank position etc, it will not fire up the fuel pump and it will not start.  Let me know what you find,  Jan