Heated Seat Inoperative
Heated Seat Inoperative
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The driver and front passenger heated seats are controlled by separate heated seat switches. The switches are located on the center console. When a heated seat switch is pressed, ground is momentarily applied through the switch contacts and the switch signal circuit to the heated seat module. In response to this signal, the heated seat module applies battery voltage through the element supply voltage circuits to the seat cushion and seat back heating elements. The module then supplies a ground through the indicator control circuits to the heated seat switch illuminating the appropriate temperature indicators.
Diagnostic Aids
In order to help identify the X1 and X2 seat heater element harness connectors, see the list below:
* The X1 harness connector is the WHITE connector.
* The X2 harness connector is the GREEN connector.
Reference Information
Schematic Reference
Heated/Cooled Seat Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Heated Seats Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Circuit/System Verification
1. Ignition ON, cycle the appropriate heated seat switch through the high, medium and low temperature positions. The heated seat should operate in all positions.
• If the heated seat is inoperative or are always ON, refer to Heated Seats Malfunction.
2. Cycle the appropriate heated seat switch through the high, medium and low positions. The heated seat switch temperature indicators should illuminate.
• If the indicators are inoperative or are always ON, refer to Headed Seat Switch Temperature Indicator Malfunction.
Circuit/System Testing
Heated Seats Malfunction
1. Ignition OFF, disconnect the harness connector at the appropriate heated seat switch.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 3 and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
3. Ignition OFF, connect the harness connector at the heated seat switch and disconnect the harness connector at the appropriate heated seat module.
4. Test for less than 5 Ohms between the ground circuit terminal 5 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
5. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 4 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 and the HTD/SEAT fuse is open, test the control circuit terminal 3 for a short to ground.
6. Verify that a test lamp illuminates between the ignition circuit terminal 10 and ground.
• If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
7. Connect a test lamp between the signal circuit terminal 2 and ground.
8. Press and release the heated seat switch. The test lamp should turn ON and OFF when the switch is pressed and released.
• If the test lamp is always OFF, test the signal circuit for a short to ground or an open/high resistance. If the circuit test normal test or replace the heated seat switch.
• If the test lamp is always ON, test the signal circuit for an short to voltage. If the circuit test normal test or replace the heated seat switch.
9. Ignition OFF, disconnect the X1 harness connector at the seat cushion heater element.
10. At the male side of the harness connector, test for less than 5 Ohms between the ground circuit terminal 2 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
11. At the female side of the harness connector, 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. Connect the X1 harness connector at the seat cushion heater element and disconnect the X2 harness connector at the seat back heater element.
13. Test for 1 - 5 Ohms between terminal 1 and terminal 4.
• If not within the specified range, test or replace the seat back heater element.
14. Connect the X2 harness connector at the seat back heater element.
15. At the heated seat module harness connector, test for infinite resistance between the signal circuit terminal 1 and ground.
• If not the specified value, test the signal circuit for a short to ground.
16. Ignition ON, verify that a test lamp does not illuminate between the terminals listed below and ground:
* Heater element control circuit terminal 3
* Heated seat temperature sensor signal circuit terminal 1
• If the test lamp illuminates, test the appropriate circuit for a short to voltage.
Note: When measuring resistance, the resistance values are based on the seat being at room temperature of 20°C (68°F).
17. Test for 1.2 k - 30 kOhms between the signal circuit terminal 1 and the low reference circuit terminal 6.
• 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 back heater element.
• If greater than the specified range, test the signal circuit and the low reference circuit for a short to voltage or open/high resistance. If the circuits test normal, test or replace the seat back heater element.
18. Test for 2 - 5 Ohms between the control circuit terminal 3 and the ground circuit terminal 5.
• If less than the specified range, test for a short between the control and ground circuits. If the circuits test normal, test or replace the seat cushion heater element.
• If greater than the specified range, test the control circuit and ground circuit for an open/high resistance. If the circuits test normal, test or replace the seat cushion heater element.
19. If all circuits test normal, replace the heated seat module.
Headed Seat Switch Temperature Indicator Malfunction
1. Ignition OFF, disconnect the harness connector at the appropriate heated seat switch.
2. Test for less than 5 Ohms between the ground circuit terminal 2 and ground.
• 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 the control circuit terminal 1 and ground.
• If the test lamp does not illuminate, refer to Interior Backlighting Malfunction (Interior Backlighting Malfunction).
4. Ignition OFF, connect the harness connector at the heated seat switch and disconnect the harness connector at the heated seat module.
5. Ignition ON, connect a test lamp between the control circuit terminals listed below and ground. The appropriate indicator should turn ON and OFF when the test lamp is connected and disconnected.
* Low control circuit terminal 9
* Medium control circuit terminal 8
* High control circuit terminal 7
• If the indicator is always ON, test the appropriate control circuit for a short to ground. If the circuit tests normal, test or replace the heated seat switch.
• If the indicator is always OFF, test the appropriate 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.
Component Testing
Heated Seat Switch
1. Ignition OFF, disconnect the harness connector at the appropriate heated seat switch switch.
2. Test for infinite resistance between the B+ terminal 3 and the signal terminal 4 with the switch in the open position.
• If not the specified value, replace the heated seat switch switch.
3. Test for less than 2 Ohms between the B+ terminal 3 and the signal terminal 4 with the switch in the closed position.
• If greater than the specified range, replace the heated seat switch.
4. Install a 3 A fused jumper wire between B+ and the B+ terminal 3.
5. Connect a test lamp between the control terminals listed below and ground. The appropriate indicator should illuminate.
* Terminal 7
* Terminal 8
* Terminal 9
• If any indicator does not illuminate, replace the heated seat switch.
Seat Heater Elements
1. Ignition OFF, disconnect the X1, X2 harness connectors at the seat cushion and seat back heater elements.
2. Test for 1 - 5 Ohms between the X1 seat cushion harness connector terminal 2 and the X2 seat back harness connector terminal 1.
• If not within the specified range, replace the seat cushion heater element.
3. Test for 1 - 5 Ohms between the seat back harness connector terminal 1 and terminal 4.
• If not within the specified range, replace the seat back heater element.
Note: When measuring resistance, the resistance values are based on the seat being at room temperature of 20°C (68°F).
4. Test for 1.2 k - 30 kOhms between terminal 2 and terminal 3.
• If not within the specified range, replace the seat back heater element.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Front Seat Heater Switch Replacement (Service and Repair)
* Driver or Passenger Seat Back Cushion Heater Replacement (Driver or Passenger Seat Back Cushion Heater Replacement)
* Driver Seat Cushion Heater Replacement (Driver Seat Cushion Heater Replacement)
* Passenger Seat Cushion Heater Replacement (Passenger Seat Cushion Heater Replacement)
* Control Module References (Programming and Relearning) for heated seat module replacement, setup, and programming