Automatic Climate Control Problem

[GlennB]

My daughter's "99 Solara SLE's air conditioning compressor does not run. It is not low refrigerant pressure. When you turn on the system, the A/C light comes on solid for a few seconds then flashes continuously. You can get error codes from the system by pressing the recirc and auto buttons while turning the ignition on. The Automatic Climate control System returns an error code 21, which according to the Haynes Repair Manual is "solar sensor".

Is this an acccurate description of error code 21? If so, what role does the solar sensor play in the logic for the A/C? I see a sensor on the passenger side of the dash that I am reconing is the solar sensor. How do I troubleshoot this, or bypass it?

Any help is appreciated

[05v6solara]

I do believe that your haynes manual should indicate where the solar sensors are.

Secondly, there is one or two on the dash.

Sorry I don't know the exact code 21 info, but if it is the solar sensor, it has to do with detecting changes in heat and how the A/C should combat it.

[GlennB]

The Haynes manual gives very little info about the automatic system. Just tells how to extract the codes and a vauge definition. The manual also does not include a wiring diagram for the automatic system.