HVAC system cooling function intermittently working

What are the settings set at when you're getting this heat coming out of the vents You should be set to low as in below 66 or whatever the blow is not a temperature low and then put the air conditioning on get out of the car with the hood up touch the compressor do you feel it running touch the fat hose It should be getting cold. Are any of these conditions met now go in the car and you should be feeling cold air hopefully coming out of the top vents that blow at your face not the defrost The first set events on your display. Your heater core should not be putting hot air in the car If so the damper door may be the problem It's computer controlled solenoid controlled whatever there's a bunch of troubleshooting steps for that If you're right near the green no don't gas up just yet. Make sure your compressors coming on with the conditions above.

 

Or, maybe before anything else, hold down the auto and the fresh/recirc buttons on the steering wheel while turning the car ig-on, and tell us any two-digit codes you see in the corner of the MFD.

Never hurts to ask the car what it thinks is going on, before we get all tangled up in guessing it ourselves.

If the car only says 00 then it has no opinion, but at least we asked.

 

The B1441 is about the air mix door thingy, not the inlet door. The good news is the mix door thingy is the one shown in yitznewton's video there, and pretty easy to get to, if you have the skinny screwdrivers.

For what might fix it after you get it out, you can look at this thread:

No, that wasn't a mouse in the heater | PriusChat

The bad news is, the B1442 and B1432 really are about the inlet door thingy, and that one is over on the other side of the heater box and a lot less easy to get to. Considerable dash disassembly may be needed to reach that one, unless someone has come up with a shortcut and I've missed it.

 

Once you have that DTC resolved, also keep in mind that intermittent AC function can be an early indicator of a failed inverter cooling water pump. This usually "working normal" then "not working normal" without the "semi-working"

 

Pay attention to what you find as you're taking it out. Before you do, can you watch it move smoothly through its range of motion, if you change the set temperature from lower to higher? (Don't expect the door to move little by little as you change temperature settings. It'll normally be all the way at one end when you set a temperature warmer than the cabin is, and swing all the way to the other end when you set a temperature cooler than the cabin is, and only take intermediate positions when the cabin temperature is pretty close to what you've set.)

Does it just move smoothly, or kind of hunt back and forth? Does it seem to be mechanically hanging up? After you remove the motor, are you able to smoothly and easily move the mechanical linkage on the HVAC box that the motor moves?

I don't think you can get the internal gears on their own. But just taking the servo apart to clean the electrical traces on the gear doesn't require getting any new gear. If that turns out to be the only issue. Which it might, or might not.

 

Unfortunately, I think this is in my very near future. I heard the hunting sound in one of the 2008s yesterday. Never a dull moment....

 

If you hear the hunting sound, you have the easy case. Just clean up the traces on the pot and enjoy the car another 100k or whatever.

Only possible wrinkle was I saw someone post a photo once where the thing had been allowed to hunt for so long before tending to it that the traces were worn clear through. That was a replace-the-servo situation.