Air conditioner blowing warm air

has it ever worked since you got it?

does the compressor come on?

do the radiator cooling fans come on?

 

Hold down the AUTO and fresh/recirculate buttons on the wheel, while turning the car ON (no foot on brake, press power button twice). Watch the screen for two-digit numbers in the corner. Any come up?

 

21 = DTC B1421, just means there wasn't strong sunlight shining on the solar sensor at the moment you asked for the codes.

23 = B1423, a diagnostic about the refrigerant pressure switch. Either there is something wrong with the switch itself or its wiring, or the switch is telling the truth and the refrigerant pressure has either dropped below 28 psi or risen above 455 psi.

In the troubleshooting steps in the repair manual, they suggest checking the actual pressure first, then for wiring or switch problems. Sometimes that order gives you a rough idea of comparative likelihood.

 

Generally on all my gen twos when I put my gauges on the air conditioning system whether it's from a cheap can of AC pro from the parts store for my $400 HVAC air conditioning gauges with nothing running and the car just sitting there I'm looking for about 88 to 95 lb on the low and or high side with the car just sitting there when the cars just sitting there there's no lower high side there's low and high side ports and both of the numbers are going to be the same on the gauges when you hook up the gauges on the low and the high side it's going to be about 88 to 94 PSI if you have that at rest you should have cold air in the compressor should come on if you check your low side car just sitting there and you only show 30 lb your system is not going to run you need to get it up to about 88 to 94 PSI at rest and that will activate your pressure switch turn the compressor on and start making cold air you are probably low on gas as in freon good luck

 

I just fixed this issue with my gen2. It would be fine if the temperature is under 85 degrees but when it’s over 85, the air wouldn’t feel cold.

went to my mechanic and they said the pressure was wrong. Evacuated all the Freon and put it all back in. Now it’s working like normal, nice and cool

 

Yes you can overcharge the electronic electric inverter compressor is very easily if you're looking for 40 on the low side you'll never see it maybe on a brand new one on every one of these I've owned used Gen 2 and 3 I have not seen over 30 on the low side and 200 and some change on the high side. And that's it if I keep trying to gas it up to bring that 30 on the low side up to anywhere near 40 the compressor will stop and I just turn it off evacuate some Freon and don't do it anymore it apparently is not working at those numbers I don't have enough of these electric compressors to know all of this but I do know they spin up and spin down a lot differently than regular compressors so I'm guessing they're just able to do what they need to do with the 30 lb on the low side and the high side still seems to be pretty normal I did this one time in the Gen 3 remove some gas got the 30 on the low and whatever it does on the high never stopped working since very boring actually

 

Just as the shop did for JC91006, the best way to correctly charge this system is to simply evacuate it, then put the correct amount of refrigerant in by weight.

 

If you could link to the source where you found "23" being something about intake air temperature, we would at least stand a chance of working out how that happened.

The code 23 from the HVAC in a Gen 2 Prius is explained on pages AC-63 to AC-66 of the repair manual (the 2006 edition that somebody shared a pdf of). Its detection condition is;

Diagnostic codes don't lie, but they also don't mean anything more than they say they mean. If you have this code and the mechanic measures the high-side pressure and it's not out of that range, then you proceed by looking for why the switch or its wiring are showing as open-circuited.

 

Recharging the AC with new refrigerant is likely to be a short term fix. There is probably a leak somewhere in the system. Pray that it isn't the evaporator.

 

that kind of sounds funny

That kind of sounds funny. I guess maybe you were overcharged no that can't be right you must have been undercharged I don't know why they just didn't add a little and see what happened rather than a rip out all of your gas and recharge it completely but I guess they vacuumed it down and did all the stuff that everybody talks about I haven't had to break mine loose yet let any gas out or any of that stuff so I don't expect there to be any air in the system and it's all working fine one of my twos was a little bit low the car is 20 years old I don't think it's ever been fooled with so rather than evacuate all the gas just to pull a vacuum just because and recharge I use something like the synthetic AC pro and I just gas it up from where it is there's no reason for me to pull a vacuum I don't see any bubbles everything looks good it's just a little low I put about a half a pound in and it's almost blowing snowflakes now I leave it alone

 

Pressures when standing still at rest AC not running mean absolutely nothing. Unless it’s completely empty or extremely low with only vapor refrigerant in the system.

if you have one drop of liquid refrigerant or 100 pounds of liquid refrigerant in your system you will have exactly the same pressure.

if it’s over 85°F outside especially if the car has just been recently ran and you have at least one drop of liquid refrigerant in your system standing still not running you will have a pressure over 85 psi

If you have one drop or 100 pounds of liquid refrigerant in your AC system here in San Francisco on a 45°F morning car not running not hot you will have a pressure of a round 45 psi.
This is normal.

this is how you can tell The Mechanic you’re bringing your vehicle to has no idea how air-conditioning works. Just guessing and using generic rules of thumb without any idea of the physics behind the properties of the refrigerant itself.

you’re most likely leak culprits on a Prius are the condenser or the evaporator. Their lies 95% of the leaks on a Prius. With the condenser being number one.

usually unfortunately A Prius should not be taken to a general repair shop. Especially for air-conditioning.

 

The funniest part is that all of that is just basic behavior of the refrigerant; there's nothing Prius-specific to it at all. If there's a tech who hasn't figured out that the pressure of liquid refrigerant at rest is simply a roundabout way of making a thermometer, that tech probably shouldn't be doing A/C work on any car.

 

My mechanic friend didn’t even charge me for the service. Hooked it up to a machine, selected the hybrid option. Machine first flushes something on the first cycle and then evacuated the Freon. Took about 30 minutes and it was finished. These AC machines are great, didn’t really have to do much.

many years ago Mechanics would have to watch everything, shake a can of Freon while putting it in. Very complicated prices compared to what they do now

 

Did that machine have, I hope, separate hoses and fittings for use with the hybrid option?

 

No, it looked to have a single set of hoses and fittings.

I’m not familiar with AC but he’s done it before on my 2010 and it seemed to be fine.

Would it matter in a recharge? No oil was being added.

 

Could not Agree with you 100% more