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Apps that do AC Diagnostics?

Discussion in 'Prius OBDII Third-Party Apps' started by LEARNER, Aug 31, 2021.

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  1. LEARNER

    LEARNER Junior Member

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    Are there any Android Apps that do AC diagnostics possibly with bluetooth sensors connected to the high and low sides along with your obd bluetooth? Maybe some temp sensors as well.

    Something to add to my arsenal in checking out newer used Priuses to buy. Not a mechanic but read a lot on Prius chat :)
     
    #1 LEARNER, Aug 31, 2021
    Last edited: Aug 31, 2021
  2. LEARNER

    LEARNER Junior Member

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    Already have learned many physical inspections and signs and symptoms to look for. This would be just additional data.
     
    #2 LEARNER, Aug 31, 2021
  3. rjparker

    rjparker Tu Humilde Sirviente

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    MeasureQuick app. But you will spend $500 or more for the pressure, line and air temperature probes. Fieldpiece probes are considered best by most. May need Techstream to properly control and test the variable capacity compressor. A proper vacuum pump and separate bluetooth or standard digital vacuum gauge is needed for repairs. Each bluetooth device will have its own app but Measurequick can integrate different pieces with separate protocols and can provide likely answers to problems. Plus it provides extra data such as current btus.

    A simple mechanical temp gauge in the cabin vent can determine ac effectiveness by itself if the ambient is sufficient to load the system.
     
    #3 rjparker, Aug 31, 2021
    Last edited: Aug 31, 2021
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  4. LEARNER

    LEARNER Junior Member

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    I have the mechanical gauge. Maybe I'll just get an affordable set of analog gauges and soapy spray and test drive the car in stop and go traffic while it still hot outside like 93 F here.
     
    #4 LEARNER, Aug 31, 2021
  5. rjparker

    rjparker Tu Humilde Sirviente

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    Mechanical gauges won't help from a diagnostic standpoint on a variable speed system. Plus it is a critically charged system, eg small volume compared to a house system, so using old gauges with hoses will deplete some refrigerant. The cheap way is the temperature from the supply vents under a hot ambient. Pay more attention to the head gasket and brake booster.
     
    #5 rjparker, Aug 31, 2021
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  6. LEARNER

    LEARNER Junior Member

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    OK Thanks. What will I be looking for in the Head gasket and brake booster? Don't know where these are but I can find out.

    Guess it pays to search for cars in the Summer :)

    Also know how to access the Prius AC Self-Diagnostic but wonder how reliable it is.
     
    #6 LEARNER, Aug 31, 2021
    Last edited: Aug 31, 2021
  7. rjparker

    rjparker Tu Humilde Sirviente

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    Gen 3 cars from 2010-15 including v wagons from 2012-17 have gen3 engines and associated systems. Many are expensive problems with head gaskets and brake boosters being the worst. Read up. 2010-14 were also bad oil burners due to piston rings. All gen3s have egrs that clog up, an expensive issue if you are not advanced diy. Gen2 did not have an egr.

    Gen3 ACs work fine most of the time.
     
    #7 rjparker, Aug 31, 2021
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  8. LEARNER

    LEARNER Junior Member

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    Thanks for the info. My 2004 Prius use to burn oil a lot until I switched to Mobile One full synthetic High Mileage and change every 3-4K miles
    Also because many idle hours (Prius Camper). Yeah I was wondering about the EGR
    I still check the oil often though as that low oil warning light comes on way to late.
     
    #8 LEARNER, Aug 31, 2021
  9. ChapmanF

    ChapmanF Senior Member

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    Checking the oil often is exactly the right idea, because in fact what you are calling the "low oil warning light" is not a "low oil" "warning". It is driven by an oil pressure switch, and if you ever see it, your engine is eating itself at that moment.

    Management of the oil has to be done by dipstick, checked often enough to ensure that you don't see that light ever. (Except when turning the car IG-ON lights it up as a test.)
     
    #9 ChapmanF, Aug 31, 2021
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  10. LEARNER

    LEARNER Junior Member

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    Yeah this happened 5-6 years ago. I stopped the car immediately and was able to get some full synthetic and filled it up. No problems since but have been monitoring for signs of damage. Also using Hybrid Assistant to monitor coolant temps on inverter and engine which are WNL. Don't know how reliable that app is. Maybe should have a sample analyzed on oil and all other fluids I'm looking into now before I throw serious money into it. Was monitoring those coolants also to maybe rule out over heating of either may be causing AC Compressor to shut off in stop and go traffic and high ambient temps but believe now it's just a bad aftermarket AC Compressor that is not fully compatibel like OEM although found a local AC specialist to take a look at everything again.

    Read other stories similar and the Prius engine pulled through although had a Saturn years ago that get extreme low oil going accross country loaded up and it threw piston rod months later despite numerous oil changes hoping to flush it in my little knowledge.

    This 2004 Prius I bought new is pretty tough. Want to make the 20 year mark but have to be realistic.
     
    #10 LEARNER, Sep 1, 2021
    Last edited: Sep 1, 2021
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