On my car stereo the navigation works but I cannot switch it over to the am/FM satellite radio or a cd

Hello, a factory equipped 2006 Acura audio and navigation unit is definitely a bit primitive in capability and subject to error and failure as it ages with use and wear. I would suggest having a repair shop for automotive audio that specializes in factory installed systems local to you have a look and assess the system operation. That is really your only option, aside from obtaining an alternative used assembly or retrofiting with a non-factory unit.