I was looking for an example like Testing GM HVAC with GM Tech2. I have an 08 CTS that has the intermittent ticking mode door actuator. After an accidental battery drain, the passenger side stopped blowing cold air although for the past few months I noticed at times it lagged behind the driver side, temp wise. The driver side had always been fine until after the battery drain. It normally starts out fine with vent temps as low as 37 deg but has begun to fade mainly when the car is started up after cabin temps are already high where it hovers around 70 deg. I plugged in the Tech 2 which I’m still fairly new to and checked the blend doors cautiously as I didn’t want to create more trouble by initiating a test that I did not fully understand.
There were no stored codes and the mode door and recirculation door appeared to have functioned normally as the values and air sound in the vents changed when they were commanded. The blend door motors however, both stayed fixed at 51 counts which I believe corresponds to the lowest temp setting of 60 deg they were set at. When I increased the console temp it also increased on the Tech 2 display but the counts did not change and... More