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Air conditioner blowing warm, fuse ?

Discussion in 'Gen 3 Prius Technical Discussion' started by dwolf, Jun 3, 2017.

  1. dwolf

    dwolf Junior Member

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    This morning the AC was fine and this afternoon it is not blowing cold but does blow warm. Before I bring it to the mechanic I wanted to try to do some novice checks with help from this forum... So I thought maybe the fuse ? I notice it's a big fuse and I was not even clear on how to check it. Is that step one ? I am not set up to see if it needs a charge so that would be the mechanic. Thanks
     

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  2. ChapmanF

    ChapmanF Senior Member

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    The first step, as so utterly boringly always, is to read the trouble codes.

    Hold down the AUTO and FRESH/RECIRC buttons together while turning the ignition ON (two power button pushes, foot off brake), then read any codes off the heat-control display.

    -Chap
     
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  3. dwolf

    dwolf Junior Member

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    If I did it correct to number 23 came up. I held down the auto and the button just to the right of it.
     
  4. ChapmanF

    ChapmanF Senior Member

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    Good work. I don't have memorized what that one means, but it will be in the repair manual, $15 for two days' access at techinfo.toyota.com. I'd look it up myself if I had other things to look up this weekend, but I don't, so I'm not paid up.

    Maybe someone on the forum will know offhand. In any case, $15 isn't much to pay for having a good idea of the issue before you get to the mechanic.

    Did you do this test in a bright or dark place? (I only ask because there is one code that refers to the solar sensor, I forget which code it is, but you always have it if you do the self-test in the dark. So if you were in the dark, it might be that one, which wouldn't be as much help.)

    -Chap
     
  5. dwolf

    dwolf Junior Member

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    It's daytime... so bright.
     
  6. ChapmanF

    ChapmanF Senior Member

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    Ok, so that's probably not the solar sensor code, so it is probably real information about your issue.

    -Chap
     
  7. AzWxGuy

    AzWxGuy Weather Guy

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    I looked it up. Had the manual excerpt for the A/C system when my compressor seized up. It says the following:

    B1423/23

    Pressure Sensor Circuit

    1. A/C pressure sensor
    2. Harness or connector between A/C pressure sensor and A/C amplifier
    3. A/C amplifier
    4. Expansion valve (blocked, stuck)
    5. Condenser (blocked, deterioration of cooling capacity due to dirt)
    6. Cooler dryer (moisture in the refrigerant cycle cannot be absorbed)
    7. Cooling fan system (condenser cannot be cooled down)
    8. A/C system (leaks, blocked)

    Some things you can check. Other things are best left to a specialist that is qualified on Toyota electric HVAC.
     
  8. ChapmanF

    ChapmanF Senior Member

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    Thanks! If the OP wants to look in the manual, of course it will have a step-by-step procedure for checking which of those 8 causes are ruled out.

    -Chap
     
  9. dwolf

    dwolf Junior Member

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    It was the AC sensor... The part was $168... Does that seem correct ? Thanks
     
  10. ChapmanF

    ChapmanF Senior Member

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    Doesn't shock me ... if I remember right, it might just be sold as an assembly with the liquid line. Is it fixed and working? What did the repair run, with labor?

    -Chap
     
  11. dwolf

    dwolf Junior Member

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    So far so good... $250
     
  12. mep70

    mep70 New Member

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    Hmm, I'm new to this chat but I just performed this and the reading was blinking "00" on the left section of the temperature screen would that be the code being referred to? No other "code" per se came up. Right? or wrong?
     
  13. ChapmanF

    ChapmanF Senior Member

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    Well, blinking 00 just means the HVAC computer has nothing in particular to tell you, so the rest of the diagnosis falls to you checking stuff the way we did before there were diagnostic codes. If it had given a code, that might have saved some time and effort.

    -Chap
     
  14. mep70

    mep70 New Member

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    Well, I unscrewed the “L” cap and pushed the needle down for a .5 sec and heard some leak out, telling me that there is at least some in there. I checked the fuzes and while it’s not clear which fuzes I should be focusing on, they all seemed fine. (If any of you know which ones specifically either under the dash or under the hood I should be looking at I would appreciate the helping hand.)

    The sight glass is difficult to decipher bubbles versus running normally.

    I have checked the interior cabin air filter and it was disgusting. So I have removed it and ordered a replacement.

    I have had a LaBra on on the front of the car for a few years and the black plastic aerodynamics underneath is still intact, it would seem the road stones damaging is a low probability.

    I’m lost now. I’d like to test add some 134a just the Freon but I have read so much about it and the “experts” on here and elsewhere suggesting 134a are all created equal versus the hybrid 134a’s I’m apprehensive now. Help.
     
  15. qdllc

    qdllc Senior Member

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    Find a reputable A/C shop and let them do their thing. Price won’t be bad if it just needs to be topped off (all A/C units lose refrigerant over time). If you have a leak, then it gets pricey, but probably still cheaper than taking it to the dealership.

    FYI...if you ever have to replace an A/C compressor, buy OEM (whatever company made the one in your car). It costs more but not much, and many aftermarket compressors burn out around the time the warranty expires...and warranties usually only pay for a replacement compressor and not all the associated costs to install and fix the system. An OEM compressor should last you as long as the original.
     
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  16. mep70

    mep70 New Member

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    I appreciate that response and I’m obviously aware of businesses that provide the service but I’m looking to narrow it down and repair on my own. Hence the deep description of what I have done to identify the issue.
     
  17. ChapmanF

    ChapmanF Senior Member

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    As long as you're positive you can get "just the Freon", this is a thinkable thought. Pure 134a is all created equal, but often what you can buy is mixed with oil that will eat your electric compressor, and that's what you'd like to avoid.

    But the thing is, air conditioners are deceptively simple-looking systems that depend very tightly on the physical properties of everything involved. The right refrigerant charge is quite a narrow range, too little doesn't work well and neither does too much, and getting it right can involve more of a tool investment than you might want to make for a one-time job. All Prii have used subcooling condensers, which make eyeballing the charge harder, and Gen 3 added the ejection-cycle evaporator, just to up the ante a little further.

    I think qdllc was probably reacting to the way the thread so far is making your diagnostic efforts look a bit scattershot; to be serious about solving this issue well, you'd probably at this point still be attending to diagnosis (still finding stuff out, not yet rushing to do stuff), and putting some time in to study the principles of the system involved (say, at the level you'd find in the tech. library section of TIS, not just googling and asking on PC) ... and for a lot of people at this point, just finding a qualified A/C shop would be the quicker and less uncertain option.

    -Chap
     
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  18. qdllc

    qdllc Senior Member

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    That, and I have used “quick fixes” from the auto parts store, they work...for a time. It’s less hassle to find a trustworthy A/C mechanic who will diagnose the problem and fix only what’s wrong.
     
  19. Peter Fanelli

    Peter Fanelli Junior Member

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    Just found this thread on the weekend, had no idea you could check the a/c system for codes. Learn something new every time I come here.
    Anyway, I have codes 21, 23 and 43. 21 is the solar sensor but it's dark and gloomy here in Tennessee today. 43 is something to do with the output door motor. 23, that could be the reason my system is not working, just quickly ran a meter over all the switch terminals and every combination comes up open circuit. Studied the manual which tells me I can prove it by bridging terminals 1 and 4 on the plug, will try this on the weekend. In the meantime I cannot find anything in the manuals about replacing the pressure switch. Does anyone know if there is a schrader valve under the pressure switch so it can be removed without losing all the refrigerant or am I looking at a recharge after replacing the switch. I have the 134a and a vacuum pump so doing a recharge is no problem, just wanting to avoid a surprise.
     
  20. ChapmanF

    ChapmanF Senior Member

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    Have you found the switch part number and looked for photos online? I am not even sure whether it is sold as a single replaceable switch, or if it is integrated with the liquid line ... post #9 had a part price of $168, which made me think maybe the latter.

    If so, it's going to be a recover and recharge....