Battery voltage is supplied at all times to the heated seat modules through the DRVR HTD SEAT fuse and the PASS HTD SEAT fuse located in the IP fuse block. This voltage is used by each module to supply power to the seat cushion and seat back heating elements. Each heated seat module is also supplied with ignition voltage through the HTD SEAT/WPR RLY fuse located in the body control module (BCM) which is controlled by the RUN CRANK relay. This voltage is used to power up each heated seat module and allows the heated seat system to operate only with the ignition in the ON position. Each heated seat module is grounded through the module ground circuit at G301 for the driver seat and G302 for the passenger seat.

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

Scan Tool Reference

Control Module References

1. Ignition ON, press the heated seat switch. The seat cushion and seat back should get warm.

⇒	If both the seat cushion and the seat back are inoperative or always ON, refer to Heated Seat Malfunction.

⇒	If just one, the seat cushion or the seat back is inoperative, refer to Seat Cushion or Seat Back Heater Element Inoperative.

2. Observe the heated seat switch temperature indicators while pressing the appropriate heated seat switch through the high and low positions. The appropriate indicators should illuminate when the switch is pressed.

⇒	If the heated seat system operates normal, but one or both of the switch temperature indicators are inoperative or always ON, refer to Heated Seat Switch Indicator Malfunction.

Heated Seat Malfunction

1. Ignition OFF, disconnect the harness connector at the appropriate heated seat switch.
2. Test for less than 5 Ω between ground circuit terminal 3 and ground.

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

3. Disconnect 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 ground circuit terminal K 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 A 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 B and ground.

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

7. Verify that a test lamp does not illuminate between the signal circuit terminal G and B+.

⇒	If the test lamp illuminates, test the signal circuit for a short to ground. If the circuit tests normal, replace the HVAC control module.

8. Connect a test lamp between the signal circuit terminal D and B+.
9. Press and release the heated seat HI/LO switch. The test lamp should turn ON and OFF when the switch is pressed and released.

⇒	If the test lamp remains ON, test the signal circuit for a short to ground. If the circuit tests normal, replace the heated seat switch.

⇒	If the test lamp is always OFF, test the signal circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the heated seat switch.

10. Connect a test lamp between B+ and the signal circuit terminal F.
11. Press and release the heated seat OFF switch. The test lamp should turn ON and OFF when the switch is pressed and released.

⇒	If the test lamp remains ON, test the signal circuit for a short to ground. If the circuit tests normal, replace the heated seat switch.

⇒	If the test lamp is always OFF, test the signal circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the heated seat switch.

12. Ignition OFF, disconnect the X2 harness connector at the heated seat module.
13. Test for infinite resistance between the control circuit terminal A and ground.

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

14. Test for 1-5 Ω between control circuit terminal A and control circuit terminal C.

⇒	If greater than the specified range, test the control circuits for an open/high resistance. If the circuits test normal, test or replace the seat cushion heater element.

⇒	If less than the specified range, test for a short between the control circuits. If the circuits test normal, test or replace the seat cushion heater element.

15. Test for 850-11.5k Ω between the signal circuit terminal F and the low reference circuit terminal D.

⇒	If greater than the specified range, test the signal and low reference circuits for a short to voltage or an open/high resistance. If the circuits test normal, test or replace the seat cushion heater element.

⇒	If less than the specified range, test for a short between the signal and low reference circuits. If the circuits test normal, test or replace the seat cushion heater element.

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

Seat Cushion or Seat Back Heater Element Inoperative

1. Ignition OFF, disconnect the harness connector at the appropriate seat cushion or seat back heater element.
2. Test for 1- 8.0 Ω between the appropriate control circuit terminals listed below:

•	Seat cushion terminal C and terminal D

•	Seat back terminal A and terminal B

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

3. At the module side of the connector, test for less than 10 Ω between the appropriate low reference control circuit terminal listed below and ground:

•	Seat cushion heater element terminal C

•	Seat back heater element terminal A

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

4. At the module side of the connector, connect a test lamp between the appropriate control circuit terminal listed below and ground:

•	Seat cushion heater element terminal D

•	Seat back heater element terminal B

5. Ignition ON, press the heated seat switch. The test lamp should turn ON.

⇒	If the test lamp does not turn ON, test the control circuit for an open/high resistance.

6. If all circuits test normal, test or replace the appropriate seat cushion or seat back heater element.

Heated Seat Switch Indicator Malfunction

1. Ignition OFF, disconnect the X1 harness connector at the appropriate heated seat module.
2. Ignition ON, observe the heated seat switch temperature indicators. Both indicators should be OFF.

⇒	If either indicator is illuminated, test the appropriate control circuit listed below for a short to voltage:

•	High temperature indicator terminal J

•	Low temperature indicator terminal H

3. Connect a test lamp between B+ and the control circuit terminals listed below. The appropriate heated seat switch indicator should illuminate.

•	High temperature indicator terminal J

•	Low temperature indicator terminal H

⇒	If the indicator does not illuminate, test the appropriate control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the heated seat switch.

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

Seat Heater Elements

1. Ignition OFF, disconnect the harness connector at the seat cushion heater element.
2. Test for 1-8 Ω between terminal A and terminal D.

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

3. Test for 850-11.5k Ω between terminal B and terminal C.

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

4. Disconnect the harness connector at the seat back heater element.
5. Test for 1-8 Ω between terminal A and terminal B.

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

Heated Seat Switch

1. Ignition OFF, disconnect the harness connector at the heated seat switch.
2. Test for infinite resistance between the ground terminal 3 and the signal terminals listed below with the switch in the open position:

•	Heated seat high/low signal terminal 4

•	Heated seat Off signal terminal 1

⇒	If not the specified value, replace the heated seat switch.

3. Test for less than 1 Ω between the ground terminal 3 and the signal terminals listed below with the appropriate switch in the closed position:

•	Heated seat high/low signal terminal 4

•	Heated seat Off signal terminal 1

⇒	If greater than the specified range, replace the heated seat switch.

4. Connect a 3 A fused jumper wire between the ground terminal 3 and ground.
5. Connect a test lamp between B+ and the control terminals listed below. The appropriate temperature indicator should illuminate.

•	High temperature indicator terminal 5

•	Low temperature indicator terminal 6

⇒	If the indicator does not illuminate, replace the heated seat switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.