Heated Seat Switch Indicator Malfunction

Heated Seat Switch Indicator Malfunction

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 module then sends a message to the memory seat module via the low speed GMLAN serial data line 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 ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Heated Seats 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)


Circuit/System Testing

1. Ignition OFF, disconnect the X4 harness connector at the appropriate door module.
2. Ignition ON, verify the heated seat switch mode indicators are not illuminated.

• If the indicators are illuminated, test the indicator control circuit of the illuminated indicator for a short to voltage.

3. Connect a 3A fused jumper wire between the low reference circuit terminal 4 and ground.
4. Connect a test lamp between B+ and each indicator control circuit listed below. Each indicator should illuminate when tested.

* Medium heat indicator terminal 1
* High heat indicator terminal 2
* Low heat indicator terminal 9
* Seat back and cushion indicator terminal 10
* Seat back only mode indicator terminal 11


• If any indicator does not illuminate, replace the heated seat switch.

5. If all indicators illuminate, replace the appropriate door module.



Repair Instructions

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

* Front Seat Heater Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for DDM or PDM replacement, setup, and programming