I preface this with the note that it’s all supposition, as I have no specific knowledge of the 401’s implementation (yet?):
As a CANBUS vehicle, I’ll concur with Shifty below and say I‘m not sure just the IMU would be enough. CANBUS communications broadcast all messages on the vehicle’s network (good!), and all modules hear them. Individual modules ”listen” for the messages appropriate to them by filtering out what they want to hear from the greater noise: like having a conversation in a loud bar. The IMU would be listening for IMU related commands, and in turn broadcasting its own responses. That said, the ECU for the pilens wouldn’t likely be programmed to broadcast anything the IMU would want to hear, because obviously it wouldn’t expect anything to be listening*. In turn, the ABS modules themselves wouldn’t* be listening for messages from the IMU in turn.
So, you may find a way to plug it into the harness, great, and you may be able to bring over other parts, but to some extent it’s the old “if a tree falls in the forest” problem. It might (again, a guess) require an entire system swap.
*That is to say, assuming KTM/HQV didn’t use the existing code as the foundation for the pilen’s code base. This could have been a clean-slate, greenfield project, or they could have scaffolded on top of the legacy code (more likely) for reasons of economy. The relevant lines could just be commented out in the ECU.
There is an active CANBUS community out there. I don’t yet have hands on my vitpilen but this avenue interests me. If you do go down this path of experimentation I’m curious to see what comes of it.