ATC ERROR – DETECTED EXCHANGE ARM BOTH UP AND DOWN.
Definition:
Message is in response to failed steps during either a tool change or a requested action as part of Diagnostics.
These messages advise that some mechanism is sensing contradictory position input states (for example, both up and down). This is either an I/O or wiring problem.
Corrective Actions:
Authorized service personnel should use Diagnostics to determine if there is a mechanical or electrical fault.