Cooled Seat Switches and Door Modules
WARNING: This page is about a different car, the 2016 GMC Acadia, 2016 Chevrolet Traverse, and 2016 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
The driver and front passenger seats are controlled by separate cool seat switches. Ground is supplied to the cool seat switch through the low reference circuit from the respective door module. The door module plays an important part of the cooled seat operation; first by relaying the selected switch inputs to the MSM, and second, by controlling the temperature indicators of the switch.
The following describes the sequence of operation of the cool seat switch, and how the door module responds to each of the switch inputs.
- High Cool Mode - When the cool seat switch is pressed once, ground is applied through the switch contacts and the switch signal circuit to the door module. In response to this signal, the door module sends a serial data message to the memory seat module (MSM). In response to this message, the MSM then sends a pulse width modulation (PWM) signal through the cool seat mode signal circuit to the ventilation cooling modules indicating the high cool command. The door module then applies a ground through the high, medium, and low indicator control circuits of the switch illuminating all 3 indicators, indicating the high cool mode.
- Medium Cool Mode - When the switch is pressed a second time, the door module signals the MSM, the MSM then relays the message to the ventilation modules of the medium cool mode request. The door module then removes the ground from the high mode indicator, leaving the medium and low indicators illuminated, indicating the medium cool mode.
- Low Cool Mode - When the switch is pressed a third time, the door module signals the MSM, the MSM then relays the message to the ventilation modules of the low cool mode request. The door module then removes the ground from the medium mode indicator, leaving the low mode indicator illuminated, indicating the low cool mode.
- System Off State - After the switch is pressed a fourth time, the door module signals the MSM, the MSM then relays the message to the ventilation modules of the system OFF request. The door module then removes the ground from the low indicator control circuit turning OFF the low mode indicator.