Sierra Denali RWD V8-6.2L (2009)
are variable resistors, their resistance changes as the temperature of the seat changes. Then based on the seat temperature, the CCSM controls the voltage
level that it applies to the TEDs and blower motors.
Diagnostic Aids
The following conditions must be met in order to perform valid tests when diagnosing the climate control seat system:
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The ignition must be cycled OFF then ON between each test in order to reset the CCSM.
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Most circuit faults will set a DTC within 1.5 minutes. However, some circuit faults may cause a performance problem in one mode and be
inoperative and set a DTC in another mode. In some cases it may take 5 minutes or more for a DTC to set. Operate the heated/cooled seat in each
of the three modes for 5 minutes or more then check for DTCs.
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The engine must be running in order to supply the CCSM with the amount of current needed to operate the heated/cool seat system.
Reference Information
Schematic Reference
Heated/Cooled Seat Schematics (See: Diagrams/Electrical Diagrams)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Heated/Cooled Seats Description and Operation (See: Description and Operation/Heated/Cooled Seats Description and Operation)
Electrical Information Reference
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Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics)
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Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics)
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Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics)
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Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Verification
1. If both, the driver and passenger heated and cooled seats are inoperative, refer to Driver and Passenger Heated/Cool Seats Inoperative.
2. Ignition ON, observe the scan tool Driver Door Switch parameters listed below while pressing and releasing the appropriate switch. The readings
should change between Inactive and Active or Off and ON.
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Seat Back Heat Mode Sw.
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Seat Cool Mode Switch
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Seat Heat Mode Sw.
‹› If the reading does not change between Inactive and Active or Off and ON, refer to the Heated and Cooled Seat Switch component test. If the
switch tests normal, replace the driver door lock/window switch.
3. Observe the scan tool Passenger Door Switch parameters listed below while pressing and releasing the appropriate switch. The readings should
change between Inactive and Active or Off and ON.
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Seat Back Heat Mode Sw.
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Seat Cool Mode Switch
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Seat Heat Mode Sw.
‹› If the reading does not change between Inactive and Active or Off and ON, refer to the Heated and Cooled Seat Switch component test. If the
switch tests normal, replace the front passenger door lock/window switch.
4. If all heated and cooled seat functions operate normal, but the heated/cooled seat switch indicators do not illuminate or are always ON, refer to the
Heated and Cooled Seat Switch component test. If the switch tests normal, replace the appropriate door lock/window switch.
Circuit/System Testing
Driver and Passenger Heated/Cool Seats Inoperative
1. Ignition OFF, disconnect the X1 harness connector at the CCSM.
2. Verify that a test lamp illuminates between the ground circuit terminal M and B+.
