Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

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. In response to this signal, the module then applies battery voltage through the element supply voltage circuits to the seat cushion and seat back heating elements. The heated seat module then supplies a ground through the appropriate indicator control circuits to the heated seat switch illuminating the appropriate indicators.

Schematic Reference

Rear Seat Schematics

Connector End View Reference

Power Seat Connector End Views

Electrical Information Reference

Scan Tool Reference

Rear Heated Seat Switch Indicators Inoperative

1. Ignition OFF, disconnect the harness connector at the heated seat switch.
2. Ignition ON, verify that a test lamp illuminates between the supply voltage circuit terminal K and ground.

⇒	If the test lamp does not illuminate, test the supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the body control module (BCM).

3. Ignition OFF, connect the harness connector to the heated seat switch.
4. Disconnect the appropriate harness connector (C3 or C4) at the rear heated seat module.
5. Ignition ON, connect a test lamp between the inoperative heated seat switch indicator control circuit and ground. The indicator should illuminate.

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

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

Heated Seat Switch Indicators Always On

1. Ignition OFF, disconnect the (C3, C4) harness connector at the rear heated seat module.
2. Ignition ON, the heated seat switch mode indicators should not be illuminated.

⇒	If illuminated, test the control circuit of the illuminated indicator for a short to ground. If the circuit tests normal, test or replace the heated seat switch.

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

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 switch in the open position.

⇒	If less than infinite, replace the heated seat switch switch.

3. Test for infinite resistance between the signal terminal A and the ground terminal J with the switch in the open position.

⇒	If less than infinite, 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 switch in the closed position.

⇒	If greater than 5 ohms, replace the heated seat switch.

5. Test for less than 5 ohms between the signal terminal A and the ground terminal J with the switch in the closed position.

⇒	If greater than 5 ohms, replace the heated seat switch.

6. Connect a 3-amp fused jumper wire between the heated seat switch supply voltage terminal K and battery voltage.
7. Connect a test lamp between the following indicator control circuits and ground. The selected indicator should illuminate.

•	Terminal B seat back only mode indicator

•	Terminal C low heat indicator

•	Terminal D medium heat indicator

•	Terminal E high heat indicator

•	Terminal H seat back cushion mode indicator

⇒	If any of the indicators do not illuminate, replace the rear heated seat switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.