Battery voltage is supplied to the climate control seat module from the IGN 3 fuse located in the left rear fuse block. This voltage is used to power up the climate control seat module allowing the heated seats to operate only when the ignition switch is in the ON position. Battery positive voltage is also supplied at all times to the climate control seat module from the RF HTD/SEATS/XM fuse located in the right rear fuse block. This voltage is used by the module to supply power to the seat heating elements and is wired directly to the front passenger vented seat blower motors if equipped with KB6. Battery positive voltage is supplied directly to the driver vented seat blower motors from the MSM fuse located in the left rear fuse block. Ground is provided to the module at ground G307.

When performing resistance measurements on the heated seat system, make sure the seats are cooled. If the seat heating elements are still warm, resistance readings may be affected.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated/Vented Seat Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, observe the scan tool HVAC Control Module heated seat switch parameters listed below while pressing and releasing the appropriate switch. The readings should change between Inactive and Active.

•	Driver Heated Seat Sw.

•	Pass. Heated Seat Sw.

⇒	If the readings do not change between the specified values, replace the HVAC control module.

2. Ignition ON, operate the driver and front passenger heated seat functions. The heated seats should operate when commanded ON.

⇒	If both, the driver and front passenger heated seats are inoperative, refer to Driver and Front Passenger Heated Seats Malfunction.

⇒	If just one of the front heated seats is inoperative, refer to Heated Seat Malfunction.

Driver and Front Passenger Heated Seats Malfunction

1. Ignition OFF, disconnect the X2 harness connector at the CCSM.
2. Ignition OFF, test for less than 5 ohms between the ground circuit terminal 6 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 3 and ground.

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

4. Ignition OFF, disconnect the X1 harness connector at the CCSM.
5. Verify that a test lamp illuminates between the B+ circuit terminal B and ground.

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

6. Connect the X1 and X2 harness connectors at the CCSM.
7. Disconnect the harness connector at the front passenger seat cushion heater element.
8. Verify that a test lamp illuminates between the low reference circuit terminal D and B+.

⇒	If the test lamp does not illuminate, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the CCSM.

9. If all circuits test normal, replace the CCSM.

Heated Seat Malfunction

1. Ignition OFF, disconnect the X2 harness connector at the CCSM.
2. Connect a test lamp between the appropriate signal circuit listed below and B+.

•	Driver heated/cooled seat mode signal terminal 8

•	Passenger heated/cooled seat mode signal terminal 7

3. Ignition ON, press the appropriate heated seat switch through the high, medium, and low positions to OFF. The test lamp should illuminate until the OFF position is reached.

⇒	If the test lamp does not illuminate, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the MSM.

⇒	If the test lamp is ON with the switch in the OFF position, test the signal circuit for a short to ground. If the circuit tests normal, replace the MSM.

4. Ignition OFF, connect the X2 harness connector at the CCSM.
5. Disconnect the harness connector at the appropriate seat cushion heater element.
6. Ignition OFF, test for less than 5 ohms between the ground circuit terminal B and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

7. At the heater element side of the connector, test for 2.0-10.0 ohms between terminal A and terminal B.

⇒	If not within the specified range, replace the seat cushion heater element.

8. At the heater element side of the connector, test for 1000-15K ohms between terminal C and terminal D.

⇒	If not within the specified range, replace the seat cushion heater element.

9. Ignition ON, at the CCSM side of the connector, test for 4.8-5.2 volts between the signal circuit terminal C and the low reference circuit terminal D.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the CCSM.

⇒	If less than the specified range, test the signal circuit and the low reference circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the CCSM.

10. Disconnect the harness connector at the seat back heater element.
11. Ignition OFF, test for less than 5 ohms between the ground circuit terminal B and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

12. At the heater element side of the connector, test for 2.0-7.5 ohms between terminal A and terminal B.

⇒	If not within the specified range, replace the seat back heater element.

13. At the CCSM side of the seat back connector, connect a test lamp between the control circuit terminal A and ground.
14. Ignition ON, press the heated seat switch through the high, medium, and low positions to OFF. The test lamp should illuminate until the OFF position is reached.

⇒	If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM.

⇒	If the test lamp is ON with the switch in the OFF position, test the control circuit for a short to voltage. If the circuit tests normal, replace the CCSM.

15. At the CCSM side of the seat cushion connector, connect a test lamp between the control circuit terminal A and ground.
16. Ignition ON, press the heated seat switch through the high, medium, and low positions to OFF. The test lamp should illuminate until the OFF position is reached.

⇒	If the test lamp does not illuminate, test the control circuit for an open/high resistance. If the circuit tests normal, replace the CCSM.

17. If all circuits test normal, replace the CCSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.