Front Heated Seat Malfunction (Dealer Installed)
Front Heated Seat Malfunction (Dealer Installed)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
Battery positive voltage and ground is supplied to the seat heating control module from the auxiliary power outlet harness connector located under the CD player. This voltage is used to power up the heated seat module and to supply power to the seat heater elements. Battery voltage is supplied to the heated seat switch from the seat heating control module. When a heated seat switch is pressed, battery voltage is applied through the switch contacts and the heated seat switch signal circuit to the seat heating control module indicating the heated seat command. In response to this signal, the seat heating control module applies battery voltage through the control circuit to the seat heater elements.
Reference Information
Schematic Reference
Heated/Cooled Seat Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Sunshade - Left Front
Description and Operation
Heated Seats Description and Operation (Dealer Installed) Heated Seats (Dealer Installed)Heated Seats Description and Operation (Factory Installed) Heated Seats (Factory Installed)
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Programming and Relearning for scan tool information
Circuit System Verification
Note: For a valid test of the heated seat operation, you must sit in the seat for at least a 5 minute period for which the heat has time to reach the seat surface.
1. Ignition ON, operate both heated seats. The seat cushion and seat back should get warm for both seats.
• If both the driver and front passenger heated seats are inoperative, refer to Driver and Passenger Heated Seats Inoperative.
• If just one of the heated seats is inoperative or always ON, refer to Heated Seat Malfunction.
2. Observe the heated seat switch temperature indicators while pressing the appropriate heated seat switch through the high, medium, and low positions. The appropriate indicators should illuminate as the switch is activated.
• If the heated seat operates normal, but one or all of the switch temperature indicators are inoperative or always ON, refer to Heated Seat Switch Indicator Malfunction.
• If three temperature indicators are flashing, there is a problem with the heating element circuit. Refer to Heated Seat Malfunction.
• If one temperature indicator is flashing, there is a problem with the temperature sensor circuit. Refer to Heated Seat Malfunction.
Circuit/System Testing
Driver and Passenger Heated Seats Inoperative
1. Ignition OFF, disconnect the X4 harness connector at the seat heating control module.
2. Test for less than 5 omhs between each ground circuit terminal listed below and ground:
* Terminal 4
* Terminal 5
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between each B+ circuit terminal listed below and ground:
* Terminal 2
* Terminal 3
* Terminal 6
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
4. Ignition OFF, connect the X2 harness connector at seat heating control module and disconnect the harness connector at the heated seat switch.
5. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 1 and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the seat heating control module.
6. If all circuits test normal, replace the seat heating control module.
Heated Seat Malfunction
1. Ignition OFF, disconnect the X5 harness connector at the seat heating control module.
2. Install a 3 A fused jumper wire between the B+ circuit terminal 1 and B+.
3. Connect a test lamp between the appropriate signal circuit terminal listed below and ground.
* Driver heated seat switch terminal 2
* Passenger heated seat switch terminal 6
4. Ignition ON, press and release the heated seat switch. The test lamp should turn ON and OFF as the switch is pressed and released.
• If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit tests normal, test or replace the heated seat switch.
• If the test lamp is always OFF, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the heated seat switch.
5. Ignition OFF, connect the X5 harness connector at the seat heating control module and disconnect the appropriate X1 or X3 harness connector at the seat heating control module.
6. Test for 800 - 300 komhs between the signal circuit terminal 3 and low reference circuit terminal 4.
• If less than the specified range, test for a short between the signal and low reference circuits. If the circuits test normal, test or replace the seat cushion heater element.
• If greater than the specified range, test the signal and low reference circuits for a short to voltage or an open/high resistance. If the circuits test normal, test or replace the seat cushion heater element.
7. Disconnect the harness connector at the seat back heating element.
Note: Element resistance must be measured twice to ensure that all failure conditions are simulated. First with the seat unoccupied, then with the seat occupied.
8. Test for 1 - 5 omhs between control the circuit terminal A and the low reference circuit terminal B.
• If not within the specified range, test or replace the seat back heating element.
9. Connect the harness connector at the seat back heating element.
Note: Element resistance must be measured twice to ensure that all failure conditions are simulated. First with the seat unoccupied, then with the seat occupied.
10. At the seat heating control module harness connector, test for 1 - 7 omhs between the control circuit terminal 1 and the low reference circuit terminal 2.
• If less than the specified range, test for a short between the control and low reference circuits. If the circuits test normal, test or replace the seat cushion heater element.
• If greater than the specified range, test the control and low reference circuits for an open/high resistance. If the circuits test normal, test or replace the seat cushion heater element.
11. Test for infinite resistance between the control circuit terminal 1 and ground.
• If not the specified value, test the control circuit for a short to ground.
12. Ignition ON, test for less than 0.1 V between the control circuit terminal 1 and ground.
• If greater than the specified value, test the control circuit for a short to voltage.
13. If all circuits test normal, replace the seat heating control module.
Heated Seat Switch Indicator Malfunction
1. Ignition OFF, disconnect the harness connector at the heated seat switch.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminals listed below and B+.
* Left seat terminal 3
* Left seat terminal 4
* Right seat terminal 6
* Right seat terminal 7
• If the test illuminates, test the appropriate control circuit for a short to ground. If the circuit tests normal, replace the seat heating control module.
3. Ignition OFF, connect the harness connector at the heated seat switch and disconnect the X5 harness connector at the seat heating control module.
4. Install a 3 A fused jumper wire between the B+ circuit terminal 1 and B+.
5. Ignition ON, connect a test lamp between each control circuit terminal listed below and ground. The appropriate temperature indicator should illuminate.
* Left seat terminal 3
* Left seat terminal 4
* Right seat terminal 7
* Right seat terminal 8
• If the indicator does not illuminate, test the 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 seat heating control module.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
For front heated seat component replacement. refer to the Accessories Manual - Front Seat Heater Kit Installation.