Battery positive voltage is supplied at all times to the heated seat module through the HTD SEAT fuse located in the rear fuse block. When commanded ON, the heated seat module uses this voltage to heat the seat heating elements. Ignition voltage is supplied to the heated seat switch and the heated seat module from the ROOF/HEAT SEAT fuse located in the BCM. The heated seat module and the seat heating elements are grounded through the module ground circuit to G303.

Each time the heated seat switch is pressed, ignition voltage is applied through the heated seat signal circuit to the heated seat module. The module counts these inputs to determine what level of heat the vehicle operator is commanding. In response to these switch signals, the heated seat module applies battery voltage and ground through the seat heater element control circuits to the seat heating elements. When the desired seat temperature has been reached, the module will open and close the supply voltage to the heater elements as necessary in order to maintain the seat temperature.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation

Electrical Information Reference

Ignition ON, operate the heated seat switch to the high and low heat positions. The seat cushion and seat back should get warm and the appropriate heated seat switch temperature indicators should illuminate.

Heated Seat Circuit Test

1. Ignition OFF, disconnect the harness connector at the appropriate heated seat switch.
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 harness connector at the heated seat switch and disconnect the X1 harness connector at the appropriate heated seat module.
4. Test for less than 5 Ω between the ground circuit terminal 1 and ground.

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

5. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 4 and ground.

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

6. 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 an open/high resistance.

7. Connect a test lamp between the signal circuit terminal 2 and ground.
8. Press and release the heated seat switch. The test lamp should turn ON and OFF when the switch is pressed and released.

⇒	If the test lamp remains OFF, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the heated seat switch.

⇒	If the test lamp is always ON, test the signal circuit for an short to voltage. If the circuit tests normal, test or replace the heated seat switch.

9. Ignition OFF, disconnect the X3 harness connector at the heated seat module.
10. Test for infinite resistance between the signal, control, and low reference circuit terminals listed below and ground:

•	Seat cushion heater element voltage control terminal 1

•	Seat cushion heater element ground control terminal 4

•	Seat cushion temperature sensor signal terminal 3

•	Seat cushion temperature sensor low reference terminal 2

⇒	If not the specified value, test the appropriate circuit for a short to ground.

11. Test for 2 k-15 kΩ between the signal circuit terminal 3 and the low reference circuit terminal 2.

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

12. Test for 0.5-5 Ω between control circuit terminal 1 and control circuit terminal 4.

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

13. Disconnect the X2 harness connector at the heated seat module.
14. Test for infinite resistance between the control circuit terminals listed below and ground:

•	Seat back heater element ground control terminal 1

•	Seat back heater element voltage control terminal 2

⇒	If not the specified value, test the appropriate circuit for a short to ground.

15. Test for 0.5-5 Ω between control circuit terminal 1 and control circuit terminal 2.

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

16. If all circuits test normal, replace the heated seat module.

Heated Seat Switch Circuit Test.

1. Ignition OFF, disconnect the harness connector at the appropriate heated seat switch.
2. Test for less than 5 Ω 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 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.

4. If all circuits test normal, test or replace the heated seat switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.