I am having problems with my dual zone climate control.

First off here are my codes:
B0361 H
B0363 H
B0365 H
B0367 H
B0441 H C
B0446 H C

If I reset the codes (or disconnect the battery, pull fuse #27) all of them come right back including the H codes.

After reseting the codes both the passenger and drivers side default to full hot. The passenger side is unresponsive to any input on the temperature ****. The drivers side is also unresponsive to input on the temperature **** and stays full hot - until I get down to 60 then it switches to full cold and if I increase the temperature setting back up it stays full cold. Meanwhile the passenger side is still full hot.

A couple notes:

1. As I decrease the temperature setting on the drivers side I can hear noises inside the dash - a plasticy clicking sound, even though the temperature remains the same coming out of the vents.

2. When the temperature is cold outside (22 F is cold to us in Dallas) and I first start the car and apply a little gas I hear a distinct buzzing or hissing (but more of a buzzing) sound coming from the passenger footwell. This only occurs under light throttle (not at idle) and seems to go away once the car warms up.

3. The mode settings all work fine - I can select between upper, lower, defrost without issue.

So what does all of this mean? Bad actuators (both drivers and passenger side)? Electrical issue?

 

Hmmmmmmmm,,,,,,, When you clear the DTCs observe the operating shaft on each actuator and see if it actually moves when the actuator cycles. My guess is the drive gear inside the actuators are cracked and no longer drive the doors. Even if it moves, it may be slipping.

 

Yep, I had that exact same gear cracked in my driver's side actuator. PITA to change out but there's no choice either. I bought mine from rockauto since it was cheaper than the GM part but it seems to work fine so far.

 

Thanks Bill.

I followed JR_VETTE's write up to get visual access to the drivers side actuator.
http://forums.corvetteforum.com/c5-t...actuators.html

While I can see the actuator, I don't know how I could possibly unscrew it without removing the dash/instrument cluster. That is a very tight fit.

I can just see the output shaft from the actuator. I put the key in and turn to ACC. The fan is on and set to the lowest setting. I clear the HVAC codes and I observe the following:

First the actuator rotates clockwise roughly 90 degrees at a pretty fast rate - takes ~5 sec. It pauses breifly and then starts to step back counter clockwise rotating ~45 degrees in short bursts. This takes about 12 sec. Lastly it finishes the last 45 degrees counter clockwise at the same speed as when it moved clockwise. After all of this the same 6 HVAC codes have returned.

My next step is to remove the dash (unless anyone has other suggestions) and pull apart the actuator. Not sure what to expect - maybe it is indexed wrong or has lost some teeth - perhaps that is why is steps backwards slower (or maybe it is supposed to do that?).

 

You don't have to remove the dash to get to it but I'll not kid you...its a PITA to do. Remove the Bose Amplifer down there, then move the hose/tube that sucks air past the temp sensor, out of the way. You'll find that laying under there, you can get a small socket on it. Again, its not easy at all but there are only two screws holding it in. Here is what I found inside of mine

 

Hey guys,

Thanks for your help on this issue. It turns out the drive gears for both passenger and drivers side actuators were cracked. I was able to repair them instead of buying new actuators and have put what I learned in a new thread:
http://forums.corvetteforum.com/c5-t...post1576656014

Thanks again!