Heated/Cooled Seats Inoperative
Heated/Cooled Seats 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.
Circuit/System Description
Battery voltage is supplied at all times to each climate control seat module (CCSM) through the HEATED SEAT LH fuse and the HEATED SEAT RH fuse located in the IP fuse block. This voltage is used by each module to supply power to the ventilation modules and the blower motor. Each CCSM is also supplied with battery voltage through the RPA / H/C SEAT fuse located in the body control module (BCM). This voltage is used to power up each module and allows the CCS system to operate only with the ignition in the ON position. Each CCSM is grounded through the module ground circuit.
Diagnostic Aids
In order to perform valid tests when diagnosing the climate control seat system, the ignition must be cycled OFF then ON between each test in order to reset the climate control seat module.
A short to ground in the heated/cool ventilation module HEAT control circuit will open the HTDST fuse when the heat mode is selected, and the heat mode will be inoperative. However, when the COOL mode is selected, the system will operate normally.
A short to ground in the heated/cool ventilation module COOL control circuit will open the HTDST fuse when the cool mode is selected and the system will be inoperative. However, when the HEAT mode is selected, the system operate normally.
Reference Information
Schematic Reference
Heated/Cooled Seat Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Heated/Cooled 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)
Scan Tool Reference
Control Module References (Programming and Relearning)
Circuit/System Testing
1. Ignition OFF, disconnect the X1 harness connector at the inoperative CCSM.
2. Ignition OFF, verify that a test lamp illuminates between B+ and the CCSM ground circuit terminal C.
• If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal D and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
4. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal B 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 BCM.
5. Ignition OFF, connect the X1 harness connector at the inoperative CCSM.
6. Disconnect the X2 harness connector at the inoperative CCSM.
7. Ignition ON, heated/cooled seats OFF, with a DMM measure the voltage at terminal 15. The voltage should measure near 12 volts.
• If less than the specified value, test the mode signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
• If greater than the specified value, test the mode signal circuit for a short to voltage. If the circuit tests normal, replace the HVAC control module.
8. Ignition OFF, connect the X2 harness connector at the inoperative CCSM.
9. Disconnect the harness connector at the appropriate heated/cooled seat blower motor.
10. Ignition ON, test for 6.0-12.0 volts between the voltage reference circuit terminal 1 and ground.
• If less than the specified range, test the voltage reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the inoperative CCSM.
• If greater than the specified range, test the voltage reference circuit for a short to voltage. If the circuit tests normal, replace the inoperative CCSM.
11. Turn the ignition OFF then ON, test for 6.0-12.0 volts between the voltage reference circuit terminal 1 and the low reference circuit terminal 4.
• If not the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the inoperative CCSM.
12. Turn the ignition OFF then ON, heated/cooled seat ON, test for 1.5-12.0 volts between the speed control circuit terminal 3 and ground.
• If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the inoperative CCSM.
• If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the inoperative CCSM.
13. Turn the ignition OFF then ON, test for 4.0-16.0 volts between the tachometer signal circuit terminal 2 and ground.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the inoperative CCSM.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the inoperative CCSM.
14. Ignition OFF, connect the harness connector at the appropriate heated/cooled seat blower motor.
15. Disconnect the X2 harness connector at CCSM.
16. Ignition OFF, test for 63.0-18K ohms of resistance between the seat cushion temperature sensor signal circuit terminal 18 and the seat cushion low reference circuit terminal 17.
• 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 inoperative seat cushion heated/cooled ventilation module.
• If less than the specified range, test the signal and low reference circuits for a short to ground. If the circuits test normal, test or replace the inoperative seat cushion heated/cooled ventilation module.
17. Ignition OFF, test for 7.5 ohms of resistance between the seat cushion heat control circuit terminal 1 and the seat cushion cool control circuit terminal 2.
• If not the specified value, test the control circuits for a short to voltage or an open/high resistance. If the circuits test normal, test or replace the inoperative seat cushion heated/cooled ventilation module.
18. Ignition OFF, test for 63.0-18K ohms of resistance between the seat back temperature sensor signal circuit terminal 19 and the seat back low reference circuit terminal 20.
• 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 inoperative seat back heated/cooled ventilation module.
• If less than the specified range, test the signal and low reference circuits for a short to ground. If the circuits test normal, test or replace the inoperative seat back heated/cooled ventilation module.
19. Ignition OFF, test for 7.5 ohms of resistance between the seat back heat control circuit terminal 11 and the seat back cool control circuit terminal 12.
• If not the specified value, test the control circuits for a short to voltage or an open/high resistance. If the circuits test normal, test or replace the inoperative seat back heated/cooled ventilation module.
20. If all circuits test normal, replace the inoperative CCSM.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Driver Seat Ventilation Heating and Cooling Blower Replacement (Driver Seat Ventilation Heating and Cooling Blower Replacement)
* Passenger Seat Ventilation Heating and Cooling Blower Replacement (Passenger Seat Ventilation Heating and Cooling Blower Replacement)
* Driver Seat Back Ventilation Heating and Cooling Module Replacement (Driver Seat Back Ventilation Heating and Cooling Module Replacement)
* Driver Seat Cushion Ventilation Heating and Cooling Module Replacement (Driver Seat Cushion Ventilation Heating and Cooling Module Replacement)
* Passenger Seat Back Ventilation Heating and Cooling Module Replacement (Passenger Seat Back Ventilation Heating and Cooling Module Replacement)
* Passenger Seat Cushion Ventilation Heating and Cooling Module Replacement (Passenger Seat Cushion Ventilation Heating and Cooling Module Replacement)
* Control Module References (Programming and Relearning)for CCSM replacement, setup, and programming