Circuit/System Description
WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
The driver and passenger vented seats are controlled by separate vented seat switches. Both switches are located in the climate control panel (CCP). When a vented seat switch is pressed, the CCP sends a GMLAN message via the serial data line to the memory seat module (MSM) indicating the vented seat command. In response to this message, the MSM then sends a pulse width modulation (PWM) signal through the vented seat mode signal circuit to the appropriate seat blower motors indicating the vented seat command. In response to this signal, the logic in the blower motors set the blower speed to the switch set point. Both blower motors then run drawing cabin air around and away from occupant.