General Description

When the mode switch is turned, a signal is sent from the HVAC control module to the vacuum control assembly. The HVAC control module provides a ground for the necessary mode actuator solenoid. This connects the desired mode actuator to vacuum. The instrument panel fuse block provides power to the vacuum control assembly through the ignition 3 voltage circuit. Ground is provided by the HVAC control module.

The HVAC control module receives power from the instrument panel fuse block on the ignition 3 voltage circuit along with the battery positive voltage circuit. The module is grounded by the ground circuit and splice pack. The HVAC control module communicates directly to the Powertrain Control Module (PCM) on the class 2 serial data and ECM/PCM/VCM class 2 serial data circuits through the splice pack.