Hybrid Powertrain Control Module

WARNING: This page is about a different car, the 2011 GMC Yukon, 2011 Chevrolet Tahoe, and 2011 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.

Location

The hybrid powertrain control module is a non-serviceable, flash-programmable micro-processor contained within the power inverter module assembly.

Operating Functions

The hybrid powertrain control module is the main controller of hybrid operation. The hybrid powertrain control module determines when to perform hybrid operation modes such as engine Auto-stop and regenerative braking. The hybrid powertrain control module also operates in conjunction with the battery energy control module to determine when to enable and disable the DC high voltage circuits. Each motor control module operates the applicable electric motor generator based upon hybrid powertrain control module commands.

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
Motor control module 1
Motor control module 2
Auxiliary transmission fluid pump control module

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:

accessory DC power control module utilizes the GM Hi-speed, Hybrid LAN communication circuit
Battery energy control module utilizes the GM Hi-speed, Hybrid LAN communication circuit
Each motor control module and the hybrid powertrain control module exchange information and commands on the SPI bus internal communication circuit as well as the hi-speed hybrid GMLAN communication circuit.
Auxiliary transmission fluid pump control module utilizes a dedicated diagnostic status circuit

In the event a hosted module communicates a fault condition, the hybrid powertrain control module will determine if hybrid operation is effected and notify the vehicle operator by requesting the MIL illuminate and/or by displaying a hybrid service required message. 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.

Circuit Inputs

In addition to GMLAN parameters, the hybrid powertrain control module directly monitors the following signal circuits:

Transmission shift selector internal mode switch (IMS) Direction and Park/Neutral switch signals
Engine crankshaft position (CKP) sensor signal
Auxiliary transmission fluid pump diagnostic circuit
High voltage interlock circuit (HVIC)

Circuit Outputs

In addition to GMLAN and SPI bus commands, the hybrid powertrain control module directly controls the following output circuits:

Auxiliary transmission fluid pump control circuit
Battery energy control module high voltage contactor relay pulse width modulated (PWM) control circuit