working with a bobcat T590 having a M4404 active warning(auxilliary no communication). No attachments will function. I have checked fuses and relays. A call to local dealer claims it's most likely the ECU. My only other thought would be a short circuit somewhere in the wire harness, but I think it's doubtful. Have no way to test ECU and doesn't make sense to have a service call and find out that's not the problem. Machine has less then 800 hours. Any thoughts?
might want to check the connectors on the aux controller and make sure they are plugged all the way in.
Also check the electric solenoid, that controls the Aux function...