if i'm not mistaken KM has to do with the keyswitch input power to the traction controller.
One thing i have seen in the past is the keyswitch connector on the back of the keyswitch switch module having a faulty connection.
Remove the steering control panel (carefully) so you can gain access to the inside where the keyswitch is and see if there are any problems with any of the connections on the keyswitch (switch module).
Getting this panel off is a challenge so be careful, you can pull out the inserts for the screws that mount it if you are not careful. A couple of the screws that hold it down are up inside and at the rear of the panel assembly and are hard to get to, i think there are 4 to remove. Once you get the panel loose you can access the screws on the panel itself to remove it's cover so you can get inside it.
Check the estop switch module also.
Make sure all the wires are in their connectors securely.