Heat no AC

Can you clarify the problem, do you have air coming out of the vents?

Code 23 - Blend door feedback circuit failure.

Try this first-
HVAC SYSTEM CALIBRATION This procedure may be performed on both the ATC and MTC system.
1. Start engine and let run.
2. If the vehicle has an ATC system, turn the control head on.
3. Set the temperature controls to the full cold position for 2 minutes.
4. Set the temperature controls to the full heat position for 5 minutes.

If no effect then it is likely the blend door actuator has failed. I hope the re-calibration works. The actuator isn't hard to replace though, remove the underdash trim panels, then remove the crews from the actuator, pull it down, remove the connectors, reverse the process to install the new one. Then perform the re-calibration above.

Thanks for the assist Steve, if the calibration doesn't work then is it probably a blend door motor that has gone bad. Make sure you check the air door operation as well when the actuator is off

Here is a guide and some diagrams (BELOW)

https://www.2carpros.com/articles/replace-blend-door-motor

Please let us know what happens.

Cheers, Ken