Rear Seat Heater Switch Indicator Malfunction
Rear Seat Heater Switch Indicator 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 left and right rear passenger heated seats are controlled by separate heated seat switches. The switches are located on the rear door panels. When a heated seat switch is pressed, ground is momentarily applied through the switch contacts and the switch signal circuit to the rear heated seat module (RHSM). In response to this signal, the RHSM applies battery voltage through the element supply voltage circuits to the seat cushion and seat back heating elements. The RHSM then supplies a ground 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 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 (Programming and Relearning)for scan tool information
Circuit/System Testing
Rear Heated Seat Switch Indicators Inoperative
1. Ignition OFF, disconnect the harness connector at the heated seat switch.
2. Ignition ON, verify that a test lamp illuminates between the supply voltage circuit terminal K and ground.
• If the test lamp does not illuminate, test the supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the body control module (BCM).
3. Ignition OFF, connect the harness connector at the heated seat switch.
4. Disconnect the X3, X4 harness connectors at the RHSM.
5. Ignition ON, connect a test lamp between the control circuits listed below and ground. The appropriate indicator should illuminate.
* Seat back and cushion mode indicator terminal 17 X4
* Seat back only mode indicator terminal 15 X4
* Low heat indicator terminal 5 X3
* Medium heat indicator terminal 16 X4
* High heat indicator terminal 4 X3
• If any indicator does not illuminate, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the heated seat switch.
6. If all circuits test normal, replace the RHSM.
Heated Seat Switch Indicators Always On
1. Ignition OFF, disconnect the X3, X4 harness connectors at the RHSM.
2. Ignition ON, heated seats OFF, the heated seat switch mode indicators should not be illuminated.
• If illuminated, test the appropriate control circuit listed below for a short to ground. If the circuit tests normal, test or replace the heated seat switch.
* Seat back and cushion mode indicator terminal 17 X4
* Seat back only mode indicator terminal 15 X4
* Low heat indicator terminal 5 X3
* Medium heat indicator terminal 16 X4
* High heat indicator terminal 4 X3
3. If all circuits test normal, replace the RHSM.
Component Testing
Rear Heated Seat Switch
1. Ignition OFF, disconnect the harness connector at the heated seat switch switch.
2. Test for infinite resistance between the signal terminal G and the ground terminal J with the seat back and cushion mode switch in the open position.
• If not the specified value, replace the heated seat switch switch.
3. Test for infinite resistance between the signal terminal A and the ground terminal J with the seat back only mode switch in the open position.
• If not the specified value, replace the heated seat switch switch.
4. Test for less than 2 ohms between the signal terminal G and the ground terminal J with the seat back and cushion mode switch in the closed position.
• If greater than the specified range, replace the heated seat switch.
5. Test for less than 2 ohms between the signal terminal A and the ground terminal J with the seat back only mode switch in the closed position.
• If greater than the specified range, replace the heated seat switch.
6. Connect a 3A fused jumper wire between the B+ terminal K and battery voltage.
7. Connect a test lamp between the control circuits listed below and ground. The selected indicator should illuminate.
* Seat back only mode indicator terminal B
* Low heat indicator terminal C
* Medium heat indicator terminal D
* High heat indicator terminal E
* Seat back cushion mode indicator terminal H
* Terminal H seat back cushion mode indicator
• If any of the indicators do not illuminate, replace the rear heated seat switch.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Rear Seat Heater Switch Replacement (Rear Seat Heater Switch Replacement)
* Control Module References (Programming and Relearning)for RHSM and BCM replacement, setup, and programming