Hey everyone, just found a nifty little trick that I'm unsure if alot of people know of. Basically the system will throw a code for the HVAC system only, not triggering a CEL (as far as I know) To do so do this:
1. Leave key out of ignition
2. Simultaneously press the on/auto button and the recirc button
3. Put key in ignition and turn to ign but not start

All the lights should and the display should flash 4 times in 1 second intervals..also, if a tone sounds there is a NEW code...if no tone, the code you may see is stored and may not have been cleared.

If you have multiple codes, the will display in ascending order..to slow this, press the fresh air button until it's slow enough for you to read

If at any point in time you want to end the diagnostics, just simply push the off button.

To cycle though all different actuator functions, just simply press the recirc button while its in diagnostics. To go through each one, one by one, press the fresh air button

Here are the codes and what they are for:
00 Normal
11 In-Vehicle Temperature Sensor Circuit
12 Ambient Air Temperature Sensor Circuit
13 Evaporator Temperature Sensor Circuit
14 Coolant Temperature Sensor Circuit
21 Solar Sensor Circuit
22 Compressor Lock Sensor Circuit
23 Pressure Switch Circuit
31 Air Mix Door Position Sensor Circuit
32 Air Inlet Door Position Sensor Circuit
33 Air Outlet Door Position Sensor Circuit
41 Air Mix Servomotor Circuit
42 Air Inlet Servomotor Circuit
43 Air Outlet Servomotor Circuit

To clear all codes, pull the DOME fuse in the engine compartment for 10 seconds, and recheck to make sure the codes have cleared

Anyway, hope this helps! There is also voltage/resistance testing and specs I can get a hold of, just let me know and I'll do my best to help.