Heated Seat Inoperative

Heated Seat Inoperative

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



Diagnostic Fault Information






Circuit/System Description

The driver and front passenger heated seats are controlled by separate heated seat switches. The switches are located on the door panels. When a heated seat switch is pressed, ground is momentarily applied through the switch contacts and the switch signal circuit to the door module. In response to this signal, the door module then sends a message via the low speed GMLAN serial data line to the memory seat module (MSM) indicating the heat seat request. The door module then applies voltage through the appropriate indicator control circuits to the heated seat switch illuminating the appropriate indicators.


Reference Information
Schematic Reference

Heated/Cooled Seat Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Heated/Vented Seat Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for Scan Tool Information


Circuit/System Verification

1. Ignition ON, observe the scan tool HVAC Driver Heated Seat Sw. parameter while pressing the driver HEATED seat switch. The readings should change between Inactive and Active.

• If not the specified value, replace the HVAC Control Module.

2. If the scan tool displays normal, there are no DTCs set, and the driver heated seat is inoperative, replace the MSM.
3. Observe the scan tool HVAC Psgr. Heated Seat Sw. parameter while pressing the passenger HEATED seat switch. The readings should change between Inactive and Active.

• If not the specified value, replace the HVAC Control Module.

4. If the scan tool displays normal, there are no DTCs set, and the passenger heated seat is inoperative, replace the MSM.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.


Control Module References (Programming and Relearning) for HVAC control module and MSM replacement, setup, and programming