Front Seat Diagnostic Procedure

DeVille (All Models)





1. Remove the front seat assembly from the vehicle. Refer to Seat Replacement (DeVille) in the Seats sub-section of the appropriate Service Manual for the removal procedure.

2. Disconnect the green 2-way connector (2) between the seat back heat element and the heated seat module located under the seat cushion assembly.

3. Measure the seat back heat element resistance between cavities A and B at the green 2-way connector. Does the resistance measure less than 5 ohms?

^ If yes, go to Step 4.

^ If no, replace the front seat back heat element. Refer to the DeVille Service Heat Element Replacement Procedure in this bulletin.

4. Disconnect the black 4-way connector (1) between the seat cushion heat element and the heated seat module located under the seat cushion assembly.

Important:
If the resistance is measured with the seat still warm, the resistance may vary outside of the specified range since the thermistor resistance varies with temperature.

5. Measure the seat cushion thermistor resistance between cavities C and D at the black 4-way connector. Does the resistance measure between 850 ohms and 11.5 K ohms?

^ If yes, go to Step 6.

^ If no, replace the front seat cushion heat element. Refer to the DeVille Service Heat Element Replacement Procedure in this bulletin.

6. Measure the seat cushion heat element resistance between cavities A and B at the black 4-way connector. Does the resistance measure less than 5 ohms?

^ If yes, the resistance values of the heat elements are within the specified range. To find the cause of the inoperative/cold heated seat, perform the standard diagnostic procedures in the appropriate Service Manual.

^ If no, replace the front seat cushion heat element. Refer to the DeVille Service Heat Element Replacement Procedure in this bulletin.

Seville/Eldorado

1. Remove the front seat assembly from the vehicle. Refer to Seat Replacement in the Seats sub-section of the appropriate Service Manual for the removal procedure.





2. Disconnect the green 2-way connector (4 or 5) between the seat back cushion upper heat element and the heated seat module (1) located under the seat cushion assembly.

3. Measure the seat back cushion upper heat element resistance between cavities A and B at the green 2-way connector. Does the resistance measure less than 5 ohms?

^ If yes, go to Step 4.

^ If no, install a front seat back cushion upper heat element. Refer to the Seville/Eldorado Service Heat Element Installation Procedure in this bulletin.

4. Disconnect the green 2-way connector (4 or 5) between the seat back cushion center heat element and the heated seat module (1) located under the seat cushion assembly.

5. Measure the seat back cushion center heat element resistance between cavities A and B at the green 2-way connector. Does the resistance measure less than 5 ohms?

^ If yes, go to Step 6.

^ If no, install a front seat back cushion center heat element. Refer to the Seville/Eldorado Service Heat Element Installation Procedure in this bulletin.

6. Disconnect the green 2-way connector (3) between the seat cushion thigh heat element and the heated seat module (1) located under the seat cushion assembly.

7. Measure the seat cushion thigh heat element resistance between cavities A and B at the green 2-way connector. Does the resistance measure less than 5 ohms?

^ If yes, go to Step 8.

^ If no, install a front seat cushion thigh heat element. Refer to the Seville/Eldorado Service Heat Element Installation Procedure in this bulletin.

8. Disconnect the black 4-way connector (2) between the seat cushion center heat element and the heated seat module located under the seat cushion assembly.

Important:
If the resistance is measured with the seat still warm, the resistance may vary outside of the specified range since the thermistor resistance varies with temperature.

9. Measure the center seat cushion thermistor resistance between cavities C and D at the black 4-way connector. Does the resistance measure between 850 ohms and 11.5 K ohms?

^ If yes, go to Step 10.

^ If no, install a front seat cushion center heat element. Refer to the Seville/Eldorado Service Heat Element Installation Procedure in this bulletin.

10. Measure the center seat cushion heat element resistance between cavities A and B at the black 4-way connector. Does the resistance measure less than 5 ohms?

^ If yes, the resistance values of the heat elements are within the specified range. To find the cause of the inoperative/cold heated seat, perform the standard diagnostic procedures in the appropriate Service Manual.

^ If no, install a front seat cushion center heat element. Refer to the Seville/Eldorado Service Heat Element Installation Procedure in this bulletin.