Tahoe 4WD V8-6.2L (2009)
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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. Ignition ON, observe the HVAC control panel while pressing and releasing the appropriate heated or cooled seat switch. The appropriate switch
symbol should be displayed on the control panel.
‹› If the symbol is not displayed, replace the HVAC control module.
2. Operate the driver and passenger heated and cooled seats through the modes of operation listed below. The seat should operate in all three modes.
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Seat back and cushion heat mode
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Back only heat mode
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Cool mode
‹› If both, the driver and passenger heated/cool seats are inoperative, refer to Driver and Passenger Heated/Cool Seats Inoperative.
‹› If the driver heated/cool seat is inoperative, refer to Driver Heated/Cool Seat Inoperative.
‹› If the passenger heated/cool seat is inoperative, refer to Passenger Heated/Cool Seat Inoperative.
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+.
‹› If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Verify that a test lamp illuminates between the B+ circuit terminal E and ground.
‹› If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
4. Disconnect the X2 harness connector at the CCSM.
5. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 1 and ground.
‹› If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
6. If all circuits test normal, replace the CCSM.
Driver Heated/Cool Seat Inoperative
1. Ignition OFF, disconnect the X1, X2, X3 harness connectors at the CCSM.
2. Connect a test lamp between the signal circuit terminal 14 X3 and B+.
3. Ignition ON, press the HEAT or COOL seat switch through the high, medium, and low positions to OFF. The test lamp should illuminate until the
OFF position is reached.
‹› If the test lamp does not illuminate, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace
the MSM.
‹› If the test lamp is ON with the switch in the OFF position, test the signal circuit for a short to ground. If the circuit tests normal, replace the
MSM.
Important: If the resistance is measured with the seat still warm or cool, the resistance values will vary. At 68°F, (20°C) the nominal
resistance value is 1200 ohms ±5 percent. For warmer or cooler ambient temperatures, refer to the Temperature vs Resistance table
below. The delta resistance values between the seat cushion and seat back temperature sensors should not be greater than 2000 ohms.
4. Ignition OFF, test for 300-18K ohms between the signal and low reference circuits listed below:
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Seat cushion temperature sensor signal circuit terminal 7 X2 and low reference circuit terminal 8 X2.
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Seat back temperature sensor signal circuit terminal 9 X2 and low reference circuit terminal 10 X2.
‹› 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 appropriate seat cushion or seat back heat/cool seat ventilation blower.
