Okay, I am done search past topics related to this. I found no actual answers to my question. I just ordered a good tested OEM CD Player (08601-47801) that is the correct part number for my model and vin number. My car has never had the CD Player installed in it. All the connections hooked up great and I double checked them too. The stereo system turns on and displays properly, and everything works, except that when I press the "Disc" button I get a message that says "External Device Not Connected". So I rechecked all the connections, and checked all the related fuses... No problems found. Does anybody know of a way to Program/Reset the head unit to accept the CD player?? Connected online with a Toyota mechanic who told me that the Head unit has to be reprogrammed to the CD unit in order for the CD to be acknowledged and work, and that I have to go to a dealership because they have the only magical device to do it. If this programming thing is correct I think that there must be a DIY way to do this without using the dealership.
I don't recall any such issue when I had my Gen 1. I didn't install a CD player, but I installed an aftermarket thingy that pretended to be the minidisc player available in some markets (it pretends to be the minidisc because that supported track titles). As soon as I had it connected right, the headunit thought there was a minidisc player and allowed using it. This is one of the situations where the diagnostic screens in the headunit are useful. People are always finding those and thinking they'll be of some use diagnosing other problems in the car, which they're not. They are just there for infotainment system diagnosis. But when that's what you're doing, they're great. So use those screens and see what device addresses show up. The repair manual lists the different addresses used by, e.g., the CD player, minidisc player, and so on. Toyota Service Information and Where To Find It | PriusChat
