Demo of warning light operations on a 2002 GM cluster.

This shows that warning lights are turned on or off by data messages, not wiring between the cluster and the various systems. As such if a communications loss happens these warning lights will turn on.
The first time I send a command to turn off the airbag warning it comes back on after about 3 or 4 seconds. This is because the cluster is not seeing the state of health (or node awake) message from the system that controls that warning light which is the SIRS module at the hex address of 0x58.
The second time the light is turned off it remains off as long as my phone, which is impersonating the SIRS module here, keeps sending the "node awake" message. A few seconds after you see the phone screen activity stop, the warning light comes back on.
The behaviour is the same for the ABS warning light but the hex address is different of course, 0x29 being the EBCM which controls the ABS system.