Hi ,This is what I would do. For the moment forget about ET and the unidentified fault.
Confirm you have 24v and a good ground at the lock solenoid. if not use a jumper wire and supply 24v directly to the solenoid and try. The hydraulics should work.
If they don't you need to check the items I mentioned in an earlier post.
If they do, you need to check that the fuse is suppling 24v to the switch, that the switch contact has closed and the continuity of the wire to the lock solenoid
Remember that ET is only monitoring the switch contact concerned with the lift kick out circuit.