VOLVO FH Gear Lever Malfunction

Hi all,

Anyone here came a cross with such us malfunction?

“gear lever malfunction” on dashboard, truck won’t start.

Have plugged in,
U114787 code popped out.

I did some research:
Check wires and connectors on between ECU and GLU/Dash GSU
Check GLU/DashGSU functionality. If still faulty, then replace GLU/DashGSU

I assume that’s electrical fault, typical for Volvo

Anybody have any idea where should I start digging ?