I did some searching through the forum and found the instructions to retrieve the heater codes. I found what code 21 means but I would like to know what code 23 means.
Refrigerant pressure switch circuit open. The switch itself should open if the refrigerant pressure goes below 196 kPa or above 3140 kPa. Of course other possibilities could be that the switch itself is flaky, or the wiring to it, or the control board. Any idea what the underhood temp was at the time you got this code? -Chap
Ok, that probably doesn't explain it then. Of course the refrigerant pressure is proportional to temperature so if it had been really wicked cold (as I could imagine in recent weeks depending on where you are) I was thinking low pressure could have been brought on that way. But 20 degrees isn't cold enough. You may have lost some refrigerant, or have one of the other causes I mentioned. At techinfo.toyota.com, Volume I of the manual is where all the diagnostic procedure charts are. If you start with that code, it will guide you through ruling out the possible causes until you've got one left. -Chap
Thanks for the advice. This past week I had a different issue to deal with. The brake light would illuminate on the dash and the engine would rev and no respond until I turned the car off. So today I'm going to clean the throttle body and hopefully that resolves that issue.