Rear Heated Seat Malfunction
Rear Heated Seat Malfunction
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 heated seat system is designed to operate with the ignition or engine ON. The left and right rear heated seat switches are located in the face plate of the rear audio control module. The rear seat heating control module located under the seat cushion (40 % side), controls the heated seat operation for both rear seats. When a heated seat switch is pressed, a serial data message is sent from the rear audio control module to the rear seat heating control module indicating the heated seat command. In response to this message, the rear seat heating control module applies battery positive voltage through the heater element supply voltage circuit and ground through the low side control circuit to the seat heating elements. The seat heating control module then sends a serial data message back to the rear audio control module to illuminate the appropriate seat temperature indicator.
Reference Information
Schematic Reference
Heated/Cooled Seat Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
Rear Heated Seats Description and Operation Rear Heated Seats
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 Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON, observe the scan tool Left Rear Seat Heating/Venting/Cooling Mode parameter while pressing the left rear HEATED seat switch. The reading should change between Off and Back & Cushion Heat.
• If not the specified value, replace the A13 rear audio control module.
2. Observe the scan tool Right Rear Seat Heating/Venting/Cooling Mode parameter while pressing the right rear HEATED seat switch. The reading should change between Off and Back & Cushion Heat.
• If not the specified value, replace the A13 rear audio control module.
3. If all scan tool parameter readings test normal, there are no DTCs set, and the left and/or right rear heated seat is inoperative, replace the K29R rear seat heating control module.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Heater and Air Conditioning and Radio Control Module Replacement Service and Repair
* Control Module References Control Module References for K29 rear seat heating control module and A13 rear audio control module replacement, setup, and programming