Code 33 = AC cut out relay circuit. This is normal if it doesn't have an AC unit.
Buy a kit at Wal-Mart or auto parts - comes with instructions
It doesn't have a cabin filter.
Replace the fuse and the relay called the CCRM (Constant Control Relay Module).
Try to replace cabin filter of vehicle.
See if you are getting voltage at the relay when you turn the AC on. Check your wiring and connectors before replacing PCM, I doubt that is your problem.
Loose or worn A/C drive belt. Tighten or replace. If serpentine belt, replace.
give location of ac relay give location of ac relay
happened to me in my 97. replaced the blower relay. in the relay box on left side under hood. costs 7.00 or so
Check the temp sensor. Also, if the AC compressor is on the radiator fan will be on, so turn off the defroster and the AC.
Toyota has issued a service bulletin that advises to replace the a/c magnetic clutch relay, it's located in the fuse/relay block under the hood near the battery: If the part number is 90987-02022, please replace the relay with the countermeasured relay P/N 90987-02028/
Replace the ac relay with your horns relay. They are the same. If it works, you can get a new relay for around fifty bucks, or ride without a horn like me.