Im having problems retrofitting Hill Descent Control in my 2014 V60 3.0 T6 AWD R-design with polestar optimization. I have seen this retrofit done on older and newer S60´s and V60´s so I thought it would be possible but no. So the problem is the following: For Hill descend control to work, I know that the car has to be AWD which I have and also the HDC button needs to be installed in the center control stack and that the automatic transmission has to be in first gear in manual mode. What I have done is, I installed the button on the center stack where it was blank (bought the button online, removed the blank and put the button there), then activated the HDC via a different software, similar to V-dash which I wont mention the name of, synced both BCM (Brake control module) and EPB (Electronic parking brake) module to the current car config, then tried it.

It didnt work, the light on the button didnt want to light up. Then I deactivated HDC and activated Hill Start Assist, synced BCM and EPB again, and Hill Start Assist worked. Then I activated both, Hill Start Asist and Hill Descent control, only Hill Start Assist worked. The HDC still didnt want to work. After that I realized, after refreshing the DTC´s in V-dash (after trying to activate HDC), the BCM would throw a lot of errors. One error I noticed is the incompatibilty. What Im wondering is, is this a hardware problem or a software problem? Because I synced the BCM and EPB to the current car config after activating each so I dont know what more to do. And my car is Automatic with AWD which is whats needed for HDC. I dont udnerstand it