08 Yukon Denali climate control issue

[Bmk928]

Having an intermittent issue with the auto climate control on our 08 Yukon Denali. On occasion none of the blend motors/modes, driver or passenger temp selector, vent selector, etc work. They freeze in the last position. Blower motors work normal and are unaffected. Tried the reset procedure by pulling the hvac/Ecas fuse, also tried the reset procedure via a tech2 I have access too as well. When looking at the hvac data in the tech2 the counts are frozen and do not respond to control changes when it’s acting up. These issues are again intermittent and function normal on occasion. Any ideas?

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics, please.

Folks will chime in with their thoughts and perspectives.

Intermittent issues on these trucks often are often created by electrical ground issues, caused by corrosion.

 

[Richard Blakely]

Having an intermittent issue with the auto climate control on our 08 Yukon Denali. On occasion none of the blend motors/modes, driver or passenger temp selector, vent selector, etc work. They freeze in the last position. Blower motors work normal and are unaffected. Tried the reset procedure by pulling the hvac/Ecas fuse, also tried the reset procedure via a tech2 I have access too as well. When looking at the hvac data in the tech2 the counts are frozen and do not respond to control changes when it’s acting up. These issues are again intermittent and function normal on occasion. Any ideas?

This happened on my 12 Tahoe. I found in drivers side headliner, a small round removable vent. Took this out and found some **** that was blocking the area. This was due to a microphone that was installed for new radio. I removed tape and repositioned microphone and replaced cover. AC has operated fine since. Suspect a temp gauge located inside headliner was providing false readings to AC due to air restriction