Manufacturer communication — 2006 GMC YUKON DENALI XL

• Applies to all 2000 - 2021 models.

  the passage

  All All 2000 - 2021 All All All All

• The A/C blows warm or A/C performance is poor.

  the passage

  Customer may comment that there A/C blows warm or they have poor A/C performance.

Steps to confirm (in the document’s order)

1. Have these readings available: A/C high and low pressures, high side sensor reading, A/C compressor duty cycle, refrigerant solenoid valve command (if equipped), outside temperature, humidity and vent temperature.

   the passage

   Please have the following information available: * A/C High and Low pressures * High side sensor reading * A/C compressor duty cycle * Refrigerant solenoid valve command in HVAC data (if equipped) * Outside temperature * Humidity * Vent temperature

2. With an automatic HVAC system, read with the scan tool the inside temperature sensor, the outside temperature sensor, the duct temperature sensors and the evaporator temperature sensor (if equipped).

   the passage

   If the unit is equipped with an Automatic HVAC system, go into the HVAC data with the scan tool and get the following readings: * Inside temperature sensor reading * Outside temperature sensor reading * Duct temperature sensor readings * Evaporator temperature sensor reading (if equipped)