Circuit/System Testing

WARNING: This page is about a different car, the 2007 Suzuki XL7. However, it is still accessible from the selected car via links, so may be relevant.

Ignition ON, use a scan tool to observe the appropriate Heated Seat Switch parameter while pressing the heated seat switch. The reading should change between Idle and Pressed.

If not, replace the HVAC control module.
If the parameter displays Pressed, replace the heated seat module.