2002 HVAC issues

[jraymer]

I am having some issues with the HVAC controls on my truck. It started with the mode door not working, blowing at feet or defrost no matter where the dial was on the dash, then at times it would just cycle through all three floor, face, and defrost on its own. I thought the mode door was the only problem but digging into it, none of the actuators are working, the fresh air door or the temp selector. I can command them all with my scan tool to work but they don't work with the havoc module. Fuses are good, I even replaced the havoc module and it didn't change anything. I also ohmed wiring from the mode door and temp actuator to the havoc plug and all seems well. Not sure where else to go with it. I have tried doing to relearn a few times and the actuators will all sweep and move except the mode so I may replace that. Can one bad actuator affect how the other ones work? I do have codes as well: B0248- Airflow control 3 circuit short to battery or open and U1500- Inter Device Dedicated BUS Fault. I have gone through the flow chart for B0248 and think it may be the actuator. I have not messed with the U1500 yet. Long post but any input from you guys would be appreciated.

 

[jraymer]

Bumping my old thread. Still having the same issues. I went a head and replaced my mode door actuator before my 2k cross country trip and that didn’t fix it. Truck is still doing the same thing but just have the 1500 code now. I may take it to the dealer to see what they can do with a tech 2.

 

[Robby Avery]

When you had the mode door actuator off did you see if the door moved freely by hand just curious? Also try pulling the hvac fuse wait 15 seconds then re-install it and see if operation is restored. If that doesn't work a actuator learn by a tech 2 might show the problem other wise it could in the wiring harness if all known parts are good and new would like to know what you find :thumb:

 

[jraymer]

Yea when I had the actuator off the flaps seems to move their full range. But using the knob on the dash the actuator would only move a fraction of its range. Using my scan tool I can get it to full sweep but once I come out of the command it goes back to shit. I have tried the relearn before but not since I installed the new actuator so maybe I will give that a try.