my radio is ON,but theres no sound also the back up BEEP the seat belts and chime ara mute.
first check your fuses and relay for radio and amp. but It also might be a bad amplifier. there have been a lot of others complaining of them going bad.
You could try a system reset by disconnecting the battery for a couple hours. Might work. Note that doing a reset can confuse the car’s computer system and cause other problems, but those are usually easily addressed by the dealership and their scan tool. Providing there aren’t any other weird electrical problems, checking the applicable fuses and making sure the speaker remains connected to the wiring harness would be where I’d start.
Reset my choice of last resort. Fuses first, Those probably all go through the radio along with blinker sound. Possible the radio is toast.
I have a 2012 Acadia Denali and had the same issues with all the sounds. Took it to the dealer and they couldn’t find out what it was. After lots of search on the web, found out it was the amplifier. Had a buddy who owns a garage put it in and all the sound is back. He said it was the third one he did this year. What he noticed was there seemed to be water that gets in and around the amplifier. Seems to be a GMC defect with no recalls. I ordered the part from Amazon.