V60 2017 T5 error TCM-P086087

[Drix]

Hello !
I bought my first Volvo which is V60 T5 Drive-E 245 HP/180 kW

When I was trying to setup my car in sport/manual gear mode I noticed that my gearbox didnt react on this.
Next I discoverd that my gear shift knob should be highlighted but currently it doesnt.

I tried to fix it and I connected to vida, run diadgostic and I saw that I have TCM-P086087 error.
I checked gear shift knob and the wire between knob and gear selector module. Wire is in good condition, knob also.
What I noticed?
The knob has highlight only for few milliseconds after start engine so also I checked the voltage on gear shift knob wire. During starting engine I had ~4.5V but after while I had voltage arround 2V.
My last step was connect only gear gnob to 5V source to verify that the knob has working highlight and knob has it.

So after my actions I said that gear shift knob is good and wire between GSM and knob also. And thats all from my side at this moment.

What or how can I diagnose else instead of just replacement gear selector module?

I will be grateful for any help in my case.
Best regards for all