A/C Diagnosis Help

Discussion in 'Gen 3 Prius Technical Discussion' started by kripley1, Jun 21, 2021.

  1. kripley1

    kripley1 New Member

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    Hi folks,

    Im in need of some help figuring out what’s really going on with the A/C in my 2010 Prius.

    Symptom:
    -When I turn on the A/C it blows warm air. No change between auto mode and manual temp/fan control.
    -Occurred about a week ago and happened all at once (A/C was blowing ice cold the day prior, then warm the next day.

    I pulled the codes and did the A/C Diag mode. I’m getting a B1423 and a 23 code on the console. Both of these refer to the pressure switch.

    I brought the car to my normal mechanic (not a Toyota / Prius specialist - this seems like a mistake). He diagnosed it as a bad compressor, evidently he put a 20a fuse where the 15 should be under the dash and that allowed it to run - this makes no sense to me given that this is an electric compressor and not belt driven, and that it runs on the high voltage system. Anyway he quoted me $1900 for a compressor replacement which I’m not ready to spend. He also recovered and recharged the refrigerant.

    After I got it back I’m still getting the same codes.

    If my logic is correct and if I trust that he recharged the system properly, then the pressure switch code should actually indicate an issue elsewhere since we know the pressure and volume are ok.

    Can anyone point me to any checks for the pressure switch itself and or the wiring for it?

    If the pressure switch is bad what is involved in the replacement? Is there a schrader valve or similar under it? Or will I need to get the system recovered and recharged?

    Any help is greatly appreciated.
     
  2. burebista

    burebista Member

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    If the guy is not a Prius mechanic ask him what oil put in your AC because Prius need ND11 oil.
     
  3. Georgina Rudkus

    Georgina Rudkus Senior Member

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    The pressure switch means that there is a low refrigerant charge and a leak somewhere. Low refrigerant will activate the pressure switch to shut down the compressor.

    The only way is to repair this is to fix the leak, evacuate the system and to refill it with the factory specified charge.

    Just adding refrigerant from a can with anything other than pure R-134a and ND11 oil might destroy the system.
     
  4. ChapmanF

    ChapmanF Senior Member

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    Well, for starters, you don't have a pressure switch but a pressure transducer, and it's a bit pricey.

    A pressure "switch" would tell the A/C computer whether the pressure is anything above x but not higher than y. The pressure transducer tells the A/C computer what the actual pressure is. You can watch it in real time in Techstream. (Sometimes that's handy in diagnosis; it's like not having to bother hooking up the high side of your manifold gauge, because you can read that pressure already.)

    There's also not a Schrader under it; the refrigerant would have to be recovered first, then recharged after.

    I'm not sure how often the pressure transducer really goes bad. There's a risk of shooting the messenger, if what it's telling you about the pressure just happens to be true, and the reason is somewhere else.
     
  5. Tombukt2

    Tombukt2 Member

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    i do a bit of ac work i run a not stock gas in my persona 13 system.. itll blow snow out vents. no shiet.. ive not looked at tecstreams pressure info . but 134 A is going to adhere to pressure stds for that density gas.. doh..im still lookin that near 40 on low side.. that should produce a very cold low side tube... fat one.. same gas in my 09 1 NZ car.. I do not know if this units an inverter type system.. not sure why id be interested in hi side pressures. unless theyres a blockage . this would wreak havoc on system fo sho.. wen system at rest theyre is no hi and lo sides ...so air or gas should be able to move thru out system un restricted. whilst comp. is off.. this is a troubleshooting clue. Are you saying higher amp fuse is starting compressor and making cold .. /////????????
     
  6. lech auto air conditionin

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    other than you have to look up the exact instructions for your 2010 Prius.

    only perform this procedure if you’re 100% sure you still have refrigerant in your system otherwise you will damage the compressor.

    Locate and download the instructions for your 2010 Prius on how to test the pin connectors of your pressure switch on your 2010

    I guess I need to make videos for every model generation Prius pressure switch and put in my media album on PriusChat for reference
     
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  7. Tombukt2

    Tombukt2 Member

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    Well I will say this I am running a non-standard gas in all my prius's Gen 2 and 3 no gas that I have used has hurt my compressor or compressors and they make ice cold air and they also run about 12 to 20 lb lower head pressure than the 134A that was in there when I got the vehicles and the air conditioning was working just getting a little sluggish I removed the gas vacuum everything down put in the gas I use and have been using for about 20 years and other Corollas and cars and gas it up and never looked back for about 8 or 9 years matter of fact my 2ZZ Corolla I gassed up in 2005 and I haven't even looked at that system until about 20 minutes ago just because I thought I'd go out and look and it runs just like factory the sight glass clears up in seconds after you turn the system on it's ice cold it's been that way for all these years still is the gas I use is a larger molecule so it's doesn't like to leak out of spaces where a smaller molecule gas would and that's that

    SM-A715F ?
     
  8. Georgina Rudkus

    Georgina Rudkus Senior Member

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    Your car. You can do anything you want. I'm sticking to Toyota service procedures and industry standards.
     
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  9. Tombukt2

    Tombukt2 Member

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    Absolutely I wish I had an air conditioning problem because that is the last thing that I've ever had to work on in any Toyota in about 40 years I've replaced one compressor on an '02 Corolla Priuses and pre-90s Corollas they lasted forever I had 500,000 on six or seven of them and placed alternators but air conditioners were fine when the black mold came along in the 134A that's when stuff started to get yucky enjoy your car

    SM-A715F ?
     
  10. Mendel Leisk

    Mendel Leisk Sand Pounder

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    Not sure there’s a connection?
     
  11. lech auto air conditionin

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    I think he’s talking about on the later year model cars as they started introducing R134

    they also started introducing tighter compacted evaporators where the pins were closer together and they stayed wet. So they started having a mold and mildew problem with stinky evaporator HVAC housing.

    it actually did not directly correspond or have anything to do with the actual refrigerant but the actual change in design because of becoming more and small and compact
     
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  12. Tombukt2

    Tombukt2 Member

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    The black mold if we remember was inside of the air conditioning system the the 134A gas and it's oil and moisture would mix and create this black mold inside wouldn't be in contact with any humans or anything this is all internal but it wreaked havoc on the receiver dryer and broke down the refrigerant and or the oil that's mixed with and made the kind of a caustic substance so this was all happening while r12 was soaring into the $70 a pound range in North Carolina so I can imagine what r12 was costing out on the West Coast so I dumped all of that and just went to a hydrocarbon blend which if you want to say it is more or less a propane types set up like they've been using in campers and military stuff for longer than I've been living practically that shut down all the internal molding and weirdness in any of my 134a systems which had completely taken over the market by this time so I just used the hydrocarbon blend which was colder had a lower head pressure at running it was a win-win oh it was possible that could catch fire your air conditioning system holds so little freon or gas that when it squats out under the hood right on your exhaust manifold if it could ignite it would be about 3 seconds worth of ignition like a flamethrower and then gone that wouldn't even be time to melt the gates emission hose under the hood. Racing and motorsports faults really do make all cars and driving better because now we have rubber hoses and various other compounds that take a whole lot more to get it burning than 3 seconds of spewed gas and slight ignition just doesn't happen your car is likely to burn up from gas leaking from a bad fuel filter drip on a fuel system more than your air conditioning whatever blow up

    SM-A715F ?
     
  13. ChapmanF

    ChapmanF Senior Member

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    Don't open that Schrader valve! It's aliiiiiiiiive!

    [​IMG]
     
  14. ASRDogman

    ASRDogman Senior Member

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    Someone did not evacuate the system before filling.
    At least 30 minutes, but 1 hour is better.
    Then filling. Mold doesn't survive without air, if I remember correctly.
    Once all the air and moisture is out and it's filled with refrigerant, the mold can't grow,
    because it's not there...

     
  15. Tombukt2

    Tombukt2 Member

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    This was happening is 1:34 was just coming online or flooding the market and they're trying to ban and take our 12 out so not a lot was known at the time I guess I don't not sure about the evacuating and discharging procedure but most everything was pulled down and new receiver dryers were installed and what have you with other HC blends and all manufacturers recommended that you didn't suck the systems down or you didn't need to you could just fill up the new receiver dryer and be good to go and with that stuff you pretty much were but I do a lot of HVAC work on larger stuff and I know the value of vacuuming the system down for moisture removal Believe me new desiccant every time etc

    SM-A715F ?
     
  16. ASRDogman

    ASRDogman Senior Member

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    I don't really understand what you are typing, sorry.
    Every manufacturer DOES recommend you evacuate the system, to get the air and moisture out.
    The rec/dryer is there to trap the little bit that is in the lines between the connections that might get in.
    It is also recommended to replace it each time the system is exposed to air.

     
  17. Tombukt2

    Tombukt2 Member

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    I will send you the instructions the manufacturers of HC12A and others have for the products that they sell and that's all I can tell you I'll try to post it up here send it direct I know the procedure I'm an HVAC guy but when these gases were being put on line about 86 or so and still today 8C12A manufacturer envirotemp I think is the people look up their instructions for all their gases covering R22R12R410NA etc get back with me

    SM-A715F ?
     
  18. mr_guy_mann

    mr_guy_mann Senior Member

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    I'm not sure what he's typing about either. The first thing that comes to mind is when some cars had catastrophic compressor failure- refrigerant, oil, and ground up aluminum would make this nasty stuff called "black death" that was very difficult to flush out.

    If I recall on some Honda CRVs, if the compressor died then the dealer sold a "kit" that was basically a complete new A/C system in a box.

    The other thing was when HFC134 first rolled out, there were problems IF you used flushing agents from R12 days then converted to 134.

    Posted via the PriusChat mobile app.
     
  19. Tombukt2

    Tombukt2 Member

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    Yes alot of that too. I was working at Goodman Toyoda in Raleigh NC at the time

    SM-A715F ?
     
  20. Tombukt2

    Tombukt2 Member

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    Envirosafe today . Point is my AC is snowflake forming cooold. Hasn't been touched in over 10 years . Pepe remark getting in my cars. Gawdanged it's literally freezing in here. Have to turn up to 80 wen reptiles in car.

    SM-A715F ?
     
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