K 2500 Yukon 4WD V8-6.0L VIN U (2000)
Housing Assembly HVAC: Testing and Inspection
Diagnosis By Symptom
Air Delivery Improper
If the Function Test or other diagnosis indicates improper air delivery or a failure in the shifting of modes when moving the mode rotary knob, Inspect
the attachment of the affected control cable at the heater module.
1. Ensure that the mode control cable connects to the mode actuator.
2. Ensure that the cable sheath is retained.
3. Observe the action of the mode control cable.
If the cause of the condition is not discovered, disconnect the mode control cable at the mode valve.
Inspect the system for the following conditions:
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Improper mode valve travel and effort
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Improper mode control cable travel at the heater module end while moving the mode rotary knob is moving.
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If the mode control cable does not move, inspect for a broken mode control cable or control assembly part.
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An unattached mode control cable end at the control assembly
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A sharp kink in the mode control cable sheath that may cause severe binding.
Heating Insufficient
