These issues are one of the hardest issues because what that is most likely indicating is the BCM is seeing an issue with a system is monitors like the seat belt or tire pressure system, etc.
However, the reason you are not seeing any indicators is because it is most likely chiming because you have an electrical issue that is causing a network communication issue. This means the network that all the modules communicate on is getting corrupt information and so the BCM thinks there is an issue so it sounds the chime.
I attached the wiring diagram for your review. The way we confirm this is to monitor the voltage on the Gray white wire and ground when the issue happens. You can do this by monitoring this from the data link connector under the dash.
Lastly, your BCM is called the comfort system central control module on this diagram.
Monday, June 22nd, 2020 AT 10:45 AM