Air Conditioning Not So Good

For anyone wondering if the Carista is worth the purchase instead of just borrowing one, you can download OBD fusion and that will clear codes and provide real-time data through the Carista. I originally bought the Carista to shut off the seat belt chimes and wondered what else I could do with it. I found OBD fusion and have since cleared codes in 2 of my co-workers Dodge/Chrysler vehicles as well as my fiancés Honda.

 

Bought my SR a week ago and really did not pay attention to the AC function as it was a relatively cool day when I bought it. Now a week later with some mid 80's whether, now noticing my AC temps are similar to what you picture with them being at best 48F to 52F. AC settings are LO, AC on and in recirculate mode. Downloaded Carista and played with the temp settings already mention here and it has not changed a thing and still have abysmal AC function.

Bought a two day TIS subscription and put a manifold gage set on it and per the TIS service info, both HI/LO pressures are in spec. Have a bi-directional ThinkTools PROs scan tool and all the PIDS for the AC showed nothing that stood out but I will admit, not a AC service expert. One thing I did notice in the SCAN tool was PIDS that will check charge state and the AC ECU will record any over or undercharging events but everything showed normal.

Going to attempt to schedule a service visit and hopefully get in next week. I cannot accept this bad of an AC function and be told "it is normal". My Jeep I traded in for this had the same r1234YF freon type system and it easily got around 36F-40F temps.

 

I wouldn’t post tis stuff

 

Deleted, thanks!

 

Not that this is the cause of the poor AC performance, but are you guys checking your cabin filters?

A few years ago, I thought the AC in my 2015 Tundra was going out. It was barely pushing any cold air on max settings. A buddy mentioned the cabin filter, which I foolishly wasn't aware of. The filter had never been replaced. When I pulled it out, it was absolutely filthy and covered in shedded dog hair. I just threw it out, and didn't bother replacing it. After that, the AC would part your hair and freeze your nuts on max settings.

I'm sure that's probably not the problem on these new Tundras, but it might be worth checking, if you haven't already.

 

so you don’t have to pay a monthly/yearly fee to Carista?

 

The fee to Carista is essentially just for access within their app to make changes like seatbelt chimes, AC temp, turn signal blinks, etc. The dongle itself is a basic OBD bluetooth interface and can be used with many other free or paid apps (Torque, OBD Fusion, etc) to do other things. The software in the app is what you're paying for, the hardware is more or less universal.

 

Thanks! Do these other apps allow you to make changes to settings in the car like Carista? Is there one that is free or doesn’t require a monthly service fee? I can check out the ones you recommended. Thanks.

 

I just got my 22 Plat and The first thing I was aware of was my AC was not that cold while set to 72. I then came across this thread. Fortunately I already had a Carista BT dongle from when I owned a Lexus. I did what another forum member said to do and now I have cold air. Easy fix. Thanks!

 

The max a current auto system can drop the ambient input temp to the output temp is 25°. So on recirc mode measure the temp in your passenger footwell and then measure a footwell output temp (shortest ductwork) A 21° to 25° delta is standard. Remember to test while driving or immediately after a drive (with airflow through the condensor up front) and with your drive mode set to Norm, not Eco.

 

I ordered Carista and tried this. It does not seem to make any difference to me. Maybe I did something wrong.

 

Did this work for you? I have tried it and I am not feeling the difference.

 

It made a noticeable improvement to my truck's AC system.

 

mine to

 

maybe double check your work, and make sure the settings got saved.

to me it made the auto setting at like 68, feel exactly right like my older truck, without this setting it was like I had to crank it down to 65 or low to get it to feel correct.

 

Thanks for responding. Mine seems to need to be on LO to get really cold or on Auto setting.

 

Question.. Does it matter what the a/c is set to when you make new setting to -2c ? Should a/c be on/off or something else?
Thanks

 

mine never comes off Auto, I just dial the temp I want. Or the system is off when Im in back window roll down mode

 

I don't think it matters. Mine was set to 68 degrees on Auto when I made the Carista calibration adjustment. It immediately started blowing colder when I saved the settings.

 

I'm reading all these posts and having flashbacks to my 3rd gen Taco. I haven't yet experienced summer in my Tundra since buying it, but the Phoenix heat will definitely test it's A/C capabilities. Toyota published a TSB for the 3rd Gen Taco's using 1234YF because when the ambient temperature was over 100 degrees the A/C wouldn't blow cold. The fix was to add an additional cooling fan (a pusher) to the front of the condenser, because 1234YF runs about 25% hotter than the old 134A. My dealership service department sucks, because I took the TSB to them and they said they could not duplicate the problem. The issue mainly arises in stop and go traffic, because there's not much airflow going over the condenser. The service manager acknowledged that the tech may not have just left the truck sitting to test it, just a short test drive. I took the service manager out to my truck with a thermometer when it was 115 outside drove the truck around the block then let it sit in front of the service bay for about 10 minutes and the vents were blowing out 76 degree air on max setting. He then stated because it was intermittent (meaning that it would cool down after driving) that the TSB wouldn't apply even though the TSB specifically stated warm air at idle. If my truck wouldn't have been a lease that was coming up to term, I would have probably just added the fan to the condenser myself.

 

I have not noticed this yet. I mine I have had a couple of hot days where I hop in and think it is hot, but I keep the AC as low as it can and cycle, and it feels cold to me. I don't measure it though. I also hardly idle in my truck, most of my mileage is all highway, and here and there riding around a farm. But I am usually too hot to tell. How are you measuring the air out of the vents?

I am curious and want to replicate this test with my truck. Albeit I am in Baton Rouge and we have a humid heat unlike Arizona. I wonder if the humidity helps dissipate some of the heat, and dry heat the compressor just struggles?

 

Easiest way is to take a meat thermometer and stick it in the center vent at idle with the air set on 68-70 degrees. The temperature of the air coming out of the vent should be 35-40 degrees lower than the outside temperature. So if it's 90 degrees outside the air coming out of the vent should be in the low to mid 50's.

 

It did!

 

Don’t use ECO mode if you want decent A/C. And have used Carista as I have.
Works well for me.

 

Are you using just in Auto mode only or does it work better in manual mode?

 

There's not really a big difference between the 2, auto mode is more refined- there's a sensor in the lower driver side dash that measures the cabin temperature to adjust to the auto mode. When you are in manual, you are manually adjusting the temperature and the fan speed opposed to the sensor doing the adjustments for you.

 

I feel like my 2017 blew more air and was colder than my new 2024...

 

I just did the -2 ac +2 ambient change and it made a HUGE difference for me. 100 here today and I was able to get COLD vs barely comfortable before.

 

(U/L by me) This is where I am at AFTER -2C Carista change. And it's only mid-80's here.... Once I bring it up a few degrees from LO, 62/64 or so, and fan speed down one notch from full, it just doesn't seem to blow very cold. No way it will keep up once we get some real heat/humidity.
I know all my other Carista changes were saved. I suppose I should go back and check....

Tomnola, did you ever get yours blowing colder?

 

This truck has a wide-open front end which likes lot of air flow- the cab and interior cools down lost faster when you have the truck cruising along.