when they installed it they just didn't set up the controls if your headunit supports steering wheel controls you can get the Metra Axess ASWC-1 from Amazon, its an adapter that plugs into your head unit and you need to tap into some wires behind the steering column.
copied from a club lib post:
How do I wire the ASWC-1 up?
ASWC RED wire to 12v Switched source
ASWC Black wire to Ground
ASWC White/Green to Ground
ASWC Gray/Red to Violet/White wire
Orange/White to Ground
From memory the orange/white and violet and white wires were behind the lower steering column cover and drivers kick panel.
Not sure about the display. Are you talking about the clock/trip computer above the head unit? they do brake a lot, mine doesn't always work.
link for amazon
https://www.amazon.c...4PJC9K?ie=UTF8*Version*=1&*entries*=0