FB, below are the automatic deactivation criteria for the 139. So, not too different. Other than the PFD indications, assuming one doesn't trip one of these wickets, the only other indication one gets when using the training mode is, upon selection, a transient deceleration of the selected "bad" engine down to about 25% and a selected transient acceleration of the other engine up to about 110% before each settle down (in actuality) to about 70% while the PFD indications continue to simulate the malfunction.
I always found it to be pretty tame in use, but we also limited our usage to pretty tightly defined criteria as per our OMs. Like many things, regulating the usage tends to keep people out of trouble.
Note
The OEI TNG will be automatically disactivated for one of
the following conditions:
- either engine set to MANUAL MODE
- either engine ENG MODE switch not in FLT
position
- NR droop below 87%
- either engine flame out
- either engine detected fault on EEC
- TORQUE LIMiter disactivated.