A/C won't turn on; Set Temperature sensor out of range 92-112F

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by ThatDudeOrion, Jul 26, 2023.

  1. ThatDudeOrion

    ThatDudeOrion Member

    Joined:
    Dec 2, 2016
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    Location:
    Central, NJ
    Vehicle:
    2011 Prius
    Model:
    Three
    Hi All, unfortunately dealing with a No A/C condition. Auto mode doesn't command A/C on, and the manual A/C button gives no result. I went through all the diagnostics i could find, the indicator test does show the LED on the A/C button illuminate during test mode. The only sensor diagnostic value i could find that was showing an out of range value was the 'Set Temperature' (D Side) reading that is supposed to be 65-85 F and correlate to the desired temp selected by the driver, where as when mine is set to 65 the sensor value is reading 92.3F and when mine is set to 85 (not that i want that right now, lol) the sensor value is reading 112.1F

    I have no idea if this is what's causing the A/C to not turn on. I would suspect that regardless of what the desired set temperature is, that the manual A/C button at the very least would command the compressor to come on, so maybe this is not the root cause, maybe it is related, maybe it is a red herring.

    So the question are, do we think that replacing the climate control module will correct the 'Set Temperature' sensor value? It seems to me like that sensor or that value is contained in the climate control unit itself, but i'm not really sure. and second, does anybody know any ideas to get the A/C to come on, even when it doesn't want to? like is there a special PID somewhere that would just command A/C on all the time, regardless of what the sensors say?
     
    #1 ThatDudeOrion, Jul 26, 2023
  2. PriusCamper

    PriusCamper Senior Member

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    Pacific Northwest, USA
    Vehicle:
    2007 Prius
    Model:
    Two
    Check your inverter coolant reservoir for turbulence... When the inverter pump doesn't work the computer will provide less power to the AC systems to keep inverter from getting to hot.
     
    #2 PriusCamper, Jul 26, 2023
  3. Tombukt2

    Tombukt2 Senior Member

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    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Do you have a way to connect a charging cable like one of those cans with the low side gauge on it Do you see around 100 lb which would be off the scale of the low side gauge on top of the can That's a good thing or do you not see that If you do see that when you push the button and the air condition is in manual forget automatic for a few minutes. Put it in low fresh air fan on high all that's running and then push the AC button It should turn green and you should hear the compressor almost immediately start up If you left your can gauge attached you can jump out of the car now and go look at that gauge it should be around 32 34 lb what do you see? If you have low pressure like 30 lb showing on the gauge with the system completely off just sitting there I don't imagine you have enough in the system to get the system running. A standing system there's no high and low sides so when you're reading the low side you're reading the whole system it's going to be around 100 lb just sitting there if it's nearly full or what the heck ever. So if you got any way to confirm any of that stuff see what's happening. Make sure you're inverter pump is working but unless it's already overheated that shouldn't make any difference I don't think it throttles back the air conditioner until heat starts to rise or something maybe like that.? And check your AC fuses Make sure all that's in order but generally I rarely have trouble with compressors in these vehicles these electric things they seem to work very well Yes they do go bad rarely.
     
    #3 Tombukt2, Jul 26, 2023
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