Shut-Down Mode is activated if serious internal or external fault is detected.
When the mode is activated, the transmission will be automatically
set to neutral as the redundant shut-down circuit cuts hydraulic
pressure to the connection. This mode is only selected if nontolerable faults occur.

U have to check what's error it is. Press M when there is error and check the Err, should be four numbers.
Turning off machine erase errors.

It might be pressure feedback sensore or one of the RPM sensors