One final thing to notice is that although the IC2 shares its physical profile and physical coupling system with the IC3 and the IR4, they are incapable of actually driving as a companion with those two "relatives". This is because the designers of the computer system which transmits the driver's commands to the engines and gearboxes have not been able to come up with a common system for all three train models. Instead, for the different types to work together, a special interface-module is required. This must be built into each trainset (except from the IC3, from which the original command-signal comes). However, due to financial issues, and the fact that it would probably not be used, it was decided not to have this module in the trains (although it can easily be added if needed).