One problem related to defogger has been reported for the 2001 GMC Yukon. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2001 GMC Yukon based on all problems reported for the 2001 Yukon.
When pushing knob of heater to blow on floor 75 percent of the air will flow into windshield, opposed to the floor. Contacted dealer. . Consumer stated when heater mode is selected for floor level, 75 percent of the heat goes on windscreen.