I had a sub and amp installed in my 2017 v6. They did disconnect the battery. It sounds great but now it has a light that says Hill assist not available, has a orange wrench that says see manual. And the cruise will not come on.
Has anyone had this problem? I took it back and they tried to reset the computer but it didn’t work.
They said they wired it in to a 12 volt wire into the factory radio . Any help appreciated,

 

A few things comes to mind with the radio install
1) They tapped into an incorrect wire to get power even though they say they got it right.
2) they tapped into the correct wire but the new head unit is drawing too much current and tripping out any sensors on the same circuit (I would guess reverse camera).
3) They nicked a wire and you now have a short somewhere (again reverse camera)
4) The ground they selected is created a feeback loop which is sending noise into the electrical system

It's also possible that none of those things apply and it's actually a sensor that needs recalibration. Crazy things happen when you disconnect a battery on cars with pitch and yaw sensors that control the traction control system. If any sensor signalrs fail their startup test, things like hill assist and cruise control will not work. You will need a scanner that can read ABS codes and Body Control Module codes to see why the wrench is lit up. It could be simple....buuuuuutttt...

Personally, I would let the shop know that if they cannot fix it you'll have to take it to the dealer and they will be responsible for any repairs if it is related to their install. Once you start messing with it, you assume responsibility and liability. They can't argue that with the dealer if you give them notice.