Mine makes some kind of strange noise, but I'm not sure if it does it on ACC. Hubby has it now, I needed the truck today - the dog was not going in my car and she had to go to the vet to be spayed. If I can remember, I'll check it when he gets home.

 

I checked mine today. It doesn't make any noise on ACC except for the radio. It does it when you turn it to "on".