First, this vehicle isn't offered in the US, so I have little to no specifics on it. However, I will try my best to help.
Because of the model year, what should be done first is a can-scan. CAN stands for controller area network. Basically, all computers and modules are tied together via a few wires and communicate with each other.
This type of scan will retrieve codes regardless of the module storing them. A basic scan tool won't do this.
Here is a link showing how it is done:
Also, since there is no reaction when you press the on/off button, it could be related to the switch. This is where it becomes difficult for me simply because I don't have wiring schematics.
Regardless, if you haven't already, perform the scan I mentioned. Let me know if there are codes retrieved. Via the web, I can gather information and try to point you in the right direction.
Friday, March 11th, 2022 AT 7:00 PM