Seat Temperature Element: Testing and Inspection

Heated Seat Inoperative

Diagnostic Instructions
^ Perform the [Diagnostic System Check - Vehicle Diagnostic Information] prior to using this diagnostic procedure. Diagnostic System Check - Vehicle Diagnostic Information
^ Review [Strategy Based Diagnosis] for an overview of the diagnostic approach. Strategy Based Diagnosis
^ [Diagnostic Procedure Instructions - Vehicle Diagnostic Information] provides an overview of each diagnostic category. Diagnostic Procedure Instructions - Vehicle Diagnostic Information

Circuit/System Description
The driver and front passenger heated seats are controlled by separate heated seat switches. Both switches are located in the climate control panel (CCP). When a heated seat switch is pressed, the CCP sends a GMLAN message via the serial data line to the heated seat module indicating the heated seat request. In response to this signal, the heated seat module activates the heated seat by applying battery voltage to the seat heating elements. The heated seat module then sends a GMLAN message back to the CCP commanding it to illuminate the appropriate seat temperature indicator.

Circuit/System Testing
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.

Repair Instructions
Perform the [Diagnostic Repair Verification - Vehicle Diagnostic Information] after completing the diagnostic procedure. Diagnostic Repair Verification - Vehicle Diagnostic Information
[Control Module References] for HVAC and heated seat control module replacement, setup, and programming Programming and Relearning