2009 Yaris AC Compressor

[Narbar]

Hello!

Is there a easy way to tell if the compressor is working?  My AC is not working and dont want to get it re-gassed if the compressor has failed.

I know in some cars when the AC kicks in you can feel the revs drop slightly on idle but I cant notice anything on this car.

Thank for your help. Dean

[Cyker]

According to my dealer it has an internal clutch and is variable displacement so isn't serviceable and doesn't have the same 'kick' as a normal compressor.

When my 2009 Yaris had AC problems, they failed to diagnose the compressor as the problem until after they'd already charged me a load of money to replace a bunch of allegedly leaking pipes, so apparently it's not something obvious.

I suspect you'd need to have some AC pressure gauges and/or ODB2 diagnostics that can pull data from the compressor/sensors to see if it's working.

If it's any help, I had one of those STP regassing things from Halfords, and noticed that the low-side pressure would sometimes go UP instead of down when the AC was running, which in hindsight seems like a sign that not all was right with the compressor!

 

[bathtub tom]

The revs go up on my '14 model and I suspect it's the same spec as the OP's. The A/C's the worse i've ever had and I had it re-gassed once to no avail (it had lost very little and was well within expectations).

[Guest]

As Cyker writes, I believe it's a swashplate (variable output) compressor with no external clutch which would show whether it was engaging/disengaging.

When my compressor "loads up" and the fan kicks on/off, there's a definite change in engine note/load at idle.

I suspect it needs dedicated gauges connecting to both high and low sides which should indicate those pressures and any change in conjunction with the compressor load.

If there is too little gas in the system the compressor operation will be blocked to prevent issues.

[TonyHSD]

In addition to all above the OP needs to seek a help from a garage and hook the ac system into ac regas machine to run a vacuum test and if it passes it will regas and hopefully the ac will run afterwards if fail then the technician should offer a help to trace where the problem is, leaks etc. perhaps these are the first steps. If low on gas the light will turn on green but the compressor won’t start and no cooling fans either. 

[Cyker]

The tricky bit will be finding a good AC specialist - My experience with my dealer's diagnostic abilities in that area would make me discourage anyone from actioning anything they suggest without a second opinion.

 

[Narbar]

Thanks for the replies it's much appreciated. 

[Guest]

I suspect even a "specialist" will just hook up a machine. Check pressures, evacuate the system, that should indicate whether it needs more refrigerant, pull a vacuum and check that doesn't decay over a few minutes.

Maybe check for potential leaks using a "sniffer". If no leaks then charge with the correct mass of gas including oil and UV dye. Fortunately, if used in 2009, it should be R134a refigerant and cheaper than the modern R1234yf or whatever comination of letters and numbers they come up with next!

[Cyker]

That's usually the way to tell they're not a specialist  

There's a guy in an industrial estate on the A5 in London who is a proper specialist - He has a machine but only uses it for routine work; For diagnostics he has a proper high/low gauge, a vacuum pump, the UV light and glasses for the dye, a chemical sniffer, and he also makes custom pipes.

That said he thought my Mk2's problem was the pipes too, and didn't think it was the compressor either, so not infallable!

 

[Guest]

Which, depending on the diagnosis, will require a machine to do the necessary. Even using a so-called specialist.

[scannerman]

Without the required gas, the system won't switch on, so first is to check if it's got enough gas. The compressor has an electrically activated clutch on its front, it will be easy to see if it works or not. With the age of your car, I suspect it's leaking somewhere, the seals get hard over time, especially if the system is not regularly used.