HVAC has no zone control after disconnection of the battery

FrankDaTank · May 22

This weekend I had the battery disconnected for a time and now when i select feet it blows out of the defrost, when I select defrost it comes out of the feet, and i cannot get it to come out of the middle at all.

Called a couple dealerships and they cant get me in for a while & state that they would need to reprogram the system.

Thought id come here to see if anyone knows of a homing or reset procedure that i can do myself to save $140+ just to have them pull it in the shop.

This is a 2019 Silverado High Country.

Edited May 22 by FrankDaTank
forgot to mention model

newdude · May 22

Alternate Method (without Scan Tool)

Note: Do not operate any HVAC controls while the HVAC control module is calibrating as this may interrupt the process. If interrupted, improper HVAC performance will result.

Ignition OFF/ Vehicle OFF.

Remove the HVAC control module fuse for a minimum of 10 s.

Install the HVAC control module fuse.

Start the vehicle.

Wait 40 s for the HVAC control module to self-calibrate.

The fuse you need to pull is FUSE F46. Its in the instrument panel fuse block on the passenger side.

repairman54 · May 23

Had this on my old '11 Tahoe with auto system. It took 3 tries after a starter change for mine to reset.

Don't be surprised if it takes a few tries for actuators to reset.

FrankDaTank · May 23

THAT DID IT!!!!

I'm a bit frustrated that out of the 3 dealerships I called none of them suggested that I try this.

You guys are the best.

repairman54 · May 23

Dealer is not going to offer free advice. They are a business first. Just like a doctor that requires some sort of office visit or zoom consultation so it's billable instead of just calling in a script like in the days of old. Come on in so we can get an hour of labor billed on a non-covered work.

SteveCZ · May 23

I had to do a similar thing on an old Buick Regal (2011). Every once in a while, the auto climate control would lose its mind, and blow hot air in the summer, or cold air in the winter. Frustrating when you started the car to either cool or warm it up.... having to pop the panel off to pull the fuse, then wait, and HOPE it worked. Glad I got rid of that thing....