Hello and welcome to the forums! The SID and the ACC units are the displays in the center of the dash that control certain functions of the car; the SID is the one at the top that shows the time, date, trip computer readout and radio display and the ACC unit is the one at the bottom that controls the dual zone temperature climate control.
Both of these have manufacturing defects in the ribbon that connects the display to the car and frequently there are problems with the displays going blank in certain areas. There are several online DIY fixes that can minimize the outages in the display but more often than not you need to remove the unit (easily done at home) and ship the piece to someone who can professionally repair them for you. Most of the companies that repair the SID charge around $100 including shipping to do it.