Seat Temperature Switch: Testing and Inspection

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, REFER TO AIR BAGS AND SEAT BELTS/AIR BAGS BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

1. Check the fused ignition switch output (run) fuse in the junction block. If OK, go to Step 2. If not OK, repair the shorted circuit or component as required and replace the faulty fuse.
2. Turn the ignition switch to the On position. Check for battery voltage at the fused ignition switch output (run) fuse in the junction block. If OK, go to Step 3. If not OK, repair the open fused ignition switch output (run) circuit to the ignition switch as required.
3. Disconnect and isolate the battery negative cable. Remove the lower center bezel from the instrument panel and disconnect the instrument panel wire harness connectors from both heated seat switch connector receptacles. Check for continuity between the ground circuit cavity of the instrument panel wire harness connector for the inoperative heated seat switch(es) and a good ground. There should be continuity. If OK, go to Step 4. If not OK, repair the open ground circuit to ground as required.
4. Reconnect the battery negative cable. Turn the ignition switch to the On position. Check for battery voltage at the fused ignition switch output (run) circuit cavity of the instrument panel wire harness connector for the inoperative heated seat switch(es). If OK, turn the ignition switch to the Off position, disconnect and isolate the battery negative cable, and go to Step 5. If not OK, repair the open fused ignition switch output (run) circuit to the junction block fuse as required.

Heated Seat Switch:

5. Test the heated seat switch(es) as shown in the Heated Seat Switch Test chart. If OK, go to Step 6. If not OK, replace the faulty heated seat switch(es).
6. Disconnect the 22-way instrument panel wire harness connector from the Body Control Module (BCM) connector receptacle. Check for continuity between the seat heater switch sensor ground circuit cavity of the instrument panel wire harness connector for the inoperative heated seat switch(es) and a good ground. There should be no continuity. If OK, go to Step 7. If not OK, repair the shorted seat heater switch sensor ground circuit as required.
7. Check for continuity between the seat heater switch sensor ground circuit cavities of the instrument panel wire harness connector for the in operative heated seat switch(es) and the 22-way instrument panel wire harness connector for the BCM. There should be continuity. If OK, go to Step 8. If not OK, repair the open seat heater switch sensor ground circuit as required.
8. Check for continuity between the seat heater switch mux circuit cavity of the instrument panel wire harness connector for the inoperative heated seat switch and a good ground. There should be no continuity. If OK, go to Step 9. If not OK, repair the shorted seat heater switch mux circuit as required.
9. Check for continuity between the seat heater switch mux circuit cavity of the instrument panel wire harness connector for the inoperative heated seat switch and the 22-way instrument panel wire harness connector for the BCM. There should be continuity. If OK, use a DRB scan tool and the proper Diagnostic Procedures to test the BCM. If not OK, repair the open seat heater switch mux circuit as required.