Buick Repair Questions? Ask a Mechanic for Answers ASAP
Hello, my name is Bobby. Thank you for the question. Did this occur right after the battery was replaced?
Thank you. After a power loss on this vehicle is is common for the programming in the HVAC module to become corrupted. You can check the fuses for this system and try reseting it. To do this remove the HVAC, HTR and AC fuses from the under hood and interior fuse boxes. Replace and blown fuses. If they are fine then remove the negative battery cable. Reinstall the fuses and then the cable and see if it resets.
Sorry for the delay. I was not online earlier. If it helped momentarily and then went back to the way that it was then it is more than likely the HVAC module. Which actuator did you replace?
The HVAC module is the control unit itself. Lets try a simple recalibration. With the key off remove the HVAC B fuse only. Leave it out for 20 seconds. Then reinstall it and turn the key on to the run position. Allow the system 1 minute to recalibrate. If it continues then you need the module.
It sounds like the module cannot hold the program very long before it gets corrupted. If it worked momentarily after the reset and then went back to the way that it was then the computer is not adjusting accordingly. Having it reprogrammed by the dealer may help.