I think the Modusystem test tool can unlock it. They are based out of the Netherlands. You can use the one tool for all the big lift companies gear and they update its software to keep it current with new models of lifts.

Modus works to Arca 1 and 2 but not for 3. But you can do most things without the usb plug

Gentlemen
I have the same problem of password. If what I did below locks the motherboard, please advise how to make it operate in normal.Only two stops lift.
1. When I reached, lift was on top floor with cam out of roller. When a call was placed at GF, Top floor door would open and close. Indicator showed 1. Lift could not move because car door was not closing.
2. I switched the lift in inspection, standing on a stool I shorted the car gate switch on car top, closed the landing door and took the lift down in inspection mode.
3. Opened the landing door and removed the shorting.
4. The lift indicator shows - -
5. Works in ERO but not taking car and lobby calls when switched to normal.
6. Ran the lift in inspection to GF into DZ to try a system reset. No effect.

Works in inspection but not in normal