Information that I know so far:
- The PLC is called the K190 module and is found under the driver's seat (see diagram below).
It uses 2 MX150 locking connectors.
comms are using a protocol called "GMLAN serial" never heard of it before nor do I know what it is but something I need to research more on.
Full pinouts for the module.
The HV sense board is located in the HVJB (see pictures of the HVJB I cracked open).
Looks like a resistor divider and TI isolator IC similar layout to the KLE on the i3.