Communication and Hosted Diagnostics
The hybrid powertrain control module is the host controller for diagnostic trouble code (DTC) information for the following control modules:
- Accessory DC power control module
- Battery energy control module (BECM)
- Motor control module 1
- Motor control module 2
- Auxiliary transmission fluid pump motor control
These modules diagnose their own operation and determine when a fault condition is present. Diagnostic status is communicated to the hybrid powertrain control module through the following circuits:
- The Accessory DC power control module a GM Hi-speed, Hybrid LAN communication circuit
- The BECM utilizes the GM Hi-speed, Hybrid LAN communication circuit
All 3 motor control modules and the hybrid powertrain control module exchange information and commands on an serial peripheral interface bus internal communication circuit as well as the hi-speed hybrid GMLAN communication circuit.
In the event a hosted module communicates a fault condition, the hybrid powertrain control module will determine if one or more operating modes are affected and notify the vehicle operator by requesting the MIL illuminate and/or by displaying a message in the Driver Information Center. In addition, the hybrid powertrain control module will store the associated DTC information for retrieval by a scan tool. Some hosted modules may require an ignition cycle to clear certain DTCs from the hybrid powertrain control module.