Acura TL 2009 Instrument panel and Audio HVAC display system.

Acura TL 2009 The brightness of the Audio HVAC display unit can’t be adjusted. The brightness of the instrument panel works fine . Both of these components work off the same brightness controller. I purchased a new controller but to no avail . Since I can’t adjust the brightness, on sunny days there is glare on the Audio HVAC display unit , therefore I can’t see the writing in the display unit.