Seat Temperature Sensor: Testing and Inspection

1. Disconnect and isolate the battery negative cable. Disconnect the 4-way heated seat cushion element wire harness connector from the power seat wire harness. The power seat wire harness connectors for the seat cushion and seat back heating elements are secured to a bracket located under the rear edge of the seat cushion frame.
2. Check for continuity between the seat sensor 5 V supply circuit cavity of the 4-way heated seat cushion element wire harness connector and the seat cushion frame. There should be no continuity. If OK, go to Step 3. If not OK, replace the faulty seat cushion cover trim and element unit.
3. Using an ohmmeter, check the resistance between the seat sensor 5 V supply circuit and the seat temperature sensor input circuit cavities of the 4-way heated seat cushion element wire harness connector. The sensor resistance should be between 14 kilo ohms at 15 °C (60 °F) and 5 kilo ohms at 30 °C (85 °F). If OK, go to Step 4. If not OK, replace the faulty seat cushion cover trim and element unit.
4. Disconnect the C1 connector of the power seat wire harness from the Heated Seat Module (HSM) or Memory Heated Seat Module (MHSM) connector receptacle. Check for continuity between the seat sensor 5 V supply circuit cavity of the 4-way power seat wire harness connector for the heated seat cushion element and the seat cushion frame. There should be no continuity. If OK, go to Step 5. If not OK, repair the shorted seat sensor 5 V supply circuit as required.
5. Check for continuity between the seat sensor 5 V supply circuit cavities of the 4-way power seat wire harness connector for the heated seat cushion element and the C1 power seat wire harness connector for the HSM or MHSM. There should be continuity. If OK, go to Step 6. If not OK, repair the open seat sensor 5 V supply circuit as required.
6. Check for continuity between the seat temperature sensor input circuit cavity of the 4-way power seat wire harness connector for the heated seat cushion element and the seat cushion frame. There should be no continuity. If OK, go to Step 7. If not OK, repair the shorted seat temperature sensor input circuit as required.
7. Check for continuity between the seat temperature sensor input circuit cavities of the 4-way power seat wire harness connector for the heated seat cushion element and the C1 power seat wire harness connector for the HSM or MHSM. There should be continuity. If OK, refer to Heated Seat Module in Electronic Control Modules. If not OK, repair the open seat temperature sensor input circuit as required.