Heated Seat Inoperative - Rear
Heated Seat Inoperative - Rear
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 switch indicators.
Reference Information
Schematic Reference
Heated/Cooled Seat Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Rear Heated Seats Description and Operation (Rear Heated Seats 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 Verification
1. Ignition ON, observe the appropriate scan tool Rear Heated Seat Module Rear Seat HVC Mode parameter while pressing the heated seat back/cushion mode switch. The reading should change between Off and Back and Cushion.
• If not Back and Cushion, refer to Circuit/System Testing.
2. Observe the appropriate scan tool Rear Seat HVC Mode parameter while pressing the heated seat back only mode switch. The reading should change between Back and Cushion and Back Only.
• If not Back Only, refer to Circuit/System Testing.
3. If all scan tool parameters test normal and there are no DTCs set, replace the RHSM.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the appropriate heated seat switch.
2. Test for less than 5 ohms between the ground circuit terminal J and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, observe the appropriate scan tool Rear Seat HVC Mode parameter. The reading should be Off.
• If not the specified value, test the signal circuits terminal A and terminal G for a short to ground. If the circuits tests normal, replace the RHSM.
4. Install a 3A fused jumper wire between the signal circuit terminal G and ground. Verify the scan tool Rear Seat HVC Mode parameter reading is Back and Cushion.
• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the RHSM.
5. Install a 3A fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool Rear Seat HVC Mode parameter reading is Back Only.
• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the RHSM.
6. If all circuits tests normal, test or replace the heated seat switch.
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 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 switch in the open position.
• If not the specified value, replace the heated seat switch switch.
4. Test for less than 5 ohms between the signal terminal G and the ground terminal J with the seat back and cushion switch in the closed position.
• If greater than the specified range, replace the heated seat switch.
5. Test for less than 5 ohms between the signal terminal A and the ground terminal J with the seat back only 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 following indicator control circuits 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
• If any indicator does 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 replacement, setup, and programming