Heated Seat Inoperative

Heated Seat Inoperative

Diagnostic Instructions

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

Diagnostic Fault Information





Circuit/System Description

The driver and passenger heated seats are controlled by separate heated seat switches located in the radio/HVAC control panel. When a heated seat switch is pressed, a serial data message is sent to the radio. The radio then serves as a gateway to transmit the serial data message to the memory seat module (MSM) indicating the heated seat command. In response to this signal, the MSM then applies or removes battery voltage through the element supply voltage circuit of the seat heating elements. The MSM then sends a serial data message back to the radio to gateway the information to the radio/HVAC control panel to either illuminate or turn off the appropriate temperature indicator.

Reference Information
Schematic Reference

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

Component Connector End Views (Connector End Views By Name)
Description and Operation

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

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the X3 harness connector at the MSM.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 5 and ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Ignition OFF, connect the X3 harness connector at the MSM.
4. Ignition ON, observe the scan tool Radio 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 radio/HVAC control panel.

5. Observe the scan tool Radio Pass. 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 radio/HVAC control panel.

6. If the scan tool readings are normal, there are no DTCs set, and the driver and/or passenger heated seat is inoperative, replace the MSM.

Repair Instructions

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

* Radio Control Assembly Replacement (with Navigation Display) (Radio Control Assembly Replacement (with Navigation Display))Radio Control Assembly Replacement (without Navigation Display) (Radio Control Assembly Replacement (without Navigation Display))
* Control Module References (Programming and Relearning) for MSM replacement, setup, and programming