Yukon Denali 2WD V8-6.0L Hybrid (2010)
‹› If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the CCSM.
13. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 5 and ground.
‹› If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
‹› 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
CCSM.
Important: The ignition must be cycled OFF then ON between each test in order to reset the CCSM.
14. Ignition OFF then ON, connect a test lamp between the control circuits listed below and ground. Press the HEAT switch when testing the heat
control circuit and the COOL switch when testing the cool control circuit. The test lamp should illuminate or slowly illuminate for approximately 4
seconds after the switch is pressed. On the heat control circuit, the test lamp may exhibit a 4 second delay before it starts to illuminate.
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Seat back heat control circuit terminal 1
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Seat back cool control circuit terminal 3
‹› If the test lamp does not illuminate, test the appropriate control circuit for a short to ground or an open/high resistance. If the circuit tests
normal, replace the CCSM.
‹› If the test lamp is always ON, test the appropriate control circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
Important: The ignition must be cycled OFF then ON between each test in order to reset the CCSM.
15. Ignition OFF then ON, connect a test lamp between the circuits listed below and ground. The test lamp should illuminate or slowly illuminate for
approximately 5 seconds after pressing the HEAT switch.
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Seat back blower control circuit terminal 2
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Seat back blower speed control circuit terminal 7
‹› If the test lamp does not illuminate, test the appropriate circuit for a short to ground or an open/high resistance. If the circuit tests normal,
replace the CCSM.
‹› If the test lamp is always ON, test the appropriate circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
16. If all circuits test normal, test or replace the appropriate seat cushion or seat back ventilation heating and cooling module.
Component Testing
Ventilation Heating and Cooling Module
1. Ignition OFF, disconnect the harness connectors at the seat cushion and seat back ventilation heating and cooling modules.
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.
2. Test for 300 Ohms - 18 kOhms between the temperature sensor signal circuit terminal 5 and the low reference circuit terminal 8.
‹› If not within the specified range, replace the ventilation heating and cooling module.
Important: The test leads must be connected in the correct polarity, otherwise lower out of range values will appear. Use the Positive
Lead for the COOL control circuit and the Negative Lead for the HEAT control circuit. If the resistance is measured with the seat still
warm or cool, the resistance values will vary even if the system was powered up for just a few seconds. The TED must be allowed to
stabilize to room temperature prior to a measurement. The conditions listed below will change the resistance to out of range values:
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The test leads are incorrectly connected.
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Air blowing across the TED
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Measuring the resistance at other than room temperature of 70°F
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Holding the TED portion of the ventilation heating and cooling module in your hand
In warmer or cooler climates where room temperature conditions of 70°F (21°C) may be unattainable, resistance values may read above
the specified range. Use a heat gun or a blower to warm or cool the TED while measuring the resistance. The resistance values should
slowly lower toward the specified range.
