Telluride threw a thermostat code a while back. Code cleared, nothing happened until last week when it threw many codes: P0076, P0079, P0082, P0085, P0598, P0445, and P0597. A/C will not come on at all, even when cleared. Most codes are different solenoid circuits low ban, 598 is a control circuit low on the thermostat heater, 445 is Evap Emission system purge control valve circuit shorted, and 597 is thermostat heater control circuit/open.
What is your mileage? It says right on the page you submitted you must include the mileage.
Most codes are different solenoid circuits low ban
Typical for Kia/Hyundai, unfortunately. Those engines and transmissions are shoddily made.
If you're having problems with your thermostat, the air conditioner more than likely won't kick on with modern HVAC systems. The air conditioner generates more heat within the vehicle's engine bay, that's partly why the fan kicks on when you turn on the AC. You're putting more load on an engine with thermostat issues (the AC puts more strain on the engine, and the engine produces more heat to compensate). The body control module won't let you do this if you're already having trouble regulating your car's running temperature.
Further, if you just willy-nilly clear a thermostat-related code, the air conditioner may not kick on until that particular item in the drive cycle has been checked. It may be a fail-safe that's been hardwired into the BCM.
445 is Evap Emission system purge control valve circuit shorted
This is a separate issue, unrelated to your problem.
The P0598 code indicates either the wiring to the thermostat is loose or corroded. You could verify this yourself. If the wires aren't corroded/loose, replace the thermostat with a new one by the same manufacturer.
