The driver and front passenger climate control seats are controlled by separate heated and cooled seat switches located on the door panels. When a heated or cool seat switch is pressed, ground is momentarily applied through the switch contacts and the switch signal circuit to the driver door module (DDM) or front passenger door module (FPDM). In response to this signal, the door module sends a serial data message to the memory seat module (MSM) indicating the heat or cool seat request. The door module then applies voltage through the appropriate indicator control circuits to the heated seat switch illuminating the appropriate indicators.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Heated/Cooled Seat Connector End Views

Electrical Information Reference

Scan Tool Reference

Ignition ON, operate the heated and cooled seat switch through all three heat and cool modes of operation. The seat should activate in the appropriate heat or cool mode and the appropriate switch indicators should illuminate until the OFF position is reached.

1. Ignition OFF, disconnect the harness connector at the appropriate heated and cooled seat switch.
2. Connect a test lamp between the appropriate control circuit terminal listed below and ground:

•	Driver seat back only heat mode indicator terminal 4

•	Driver seat cool mode indicator terminal 7

•	Driver seat back and cushion heat mode indicator terminal 2

•	Driver low temperature indicator terminal 13

•	Driver medium temperature indicator terminal 6

•	Driver high temperature indicator terminal 12

•	Passenger seat back only heat mode indicator terminal 4

•	Passenger seat cool mode indicator terminal 1

•	Passenger seat back and cushion heat mode indicator terminal 6

•	Passenger low temperature indicator terminal 9

•	Passenger medium temperature indicator terminal 2

•	Passenger high temperature indicator terminal 10

3. Ignition ON, command the Door Switch Heated Seat Indicators ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp remains On, test the control circuit for a short to voltage. If the circuit tests normal, replace the door module.

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the door module.

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

Driver Heated and Cooled Seat Switch Indicator Test

1. Ignition OFF, disconnect the harness connector at the driver heated and cooled seat switch.
2. Connect a 3A fused jumper wire between the low reference circuit terminal 3 and ground.
3. Connect a test lamp between B+ and each control circuit terminal listed below. The appropriate indicator should illuminate.

•	Seat back and cushion heat mode indicator terminal 2

•	Seat back only heat mode indicator terminal 4

•	Seat cool mode indicator terminal 7

•	Low temperature indicator terminal 13

•	Medium temperature indicator terminal 6

•	High temperature indicator terminal 12

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

Passenger Heated and Cooled Seat Switch Indicator Test

1. Ignition OFF, disconnect the harness connector at the passenger heated and cooled seat switch.
2. Connect a 3A fused jumper wire between the low reference circuit terminal 5 and ground.
3. Connect a test lamp between B+ and each control circuit terminal listed below. The appropriate indicator should illuminate.

•	Seat back and cushion heat mode indicator terminal 6

•	Seat back only heat mode indicator terminal 4

•	Seat cool mode indicator terminal 1

•	Low temperature indicator terminal 9

•	Medium temperature indicator terminal 2

•	High temperature indicator terminal 10

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.