fabchef

Hi guys, so on my 09 rx, i find the temp setting and the air temp coming out are not where they should be. Example: if i set temp to 24 degrees (hot) the air coming out is cool or cold. The next time I start the car it will be hot. Is there something i’m doi Wrong?
thanks
fab

DennisMik

You are not doing anything wrong, the car is screwing up. Is the dash correctly showing the temperature you are trying to set it to? Does the air on the passenger side vents blow out at the same temperature as the driver side vents? I would guess that maybe the air mix servo motor control circuit is having a problem.

fabchef

Air is coming out of both driver and passanger side at same temp settings. I’m not running the a/c either. Was thinking...could it be an issue with the thermometer that reads the cabin temperature? Maybe acting up?
As i said, it might blow warm air one time and not the next time...
fab

DennisMik

I suppose the cabin temperature sensor (the thermometer as you called it) could be the culprit. My limited experience with these has always shown them to be constantly screwed up, never intermittent.

But in regards to this sensor, maybe the air flow to it is blocked. There is a small grill in the lower dash between the steering wheel and the center console. Air is sucked through this grille via a vacuum to the cabin temperature. If this grille or tube is plugged or maybe the vacuum source is plugged/disconnected, you would have temperature regulation problems.

tomr51

Tick for Dennismik above. the sensor is generic and cheap to replace

mnewxcv

I've noticed a large difference in temp between using recirculate VS not. Not sure why that is, but I usually just raise the temp 3 or 4 degrees if using recirc to compensate.

fabchef

Update... so i opened the tiny screen (below steering wheel) where the thermometer is. It seemed to have a thin layer of dust on it, I cleaned it off with a qtip and even took the air compressor to it.
I started the car and turned fan speed up, i took a tiny piece of paper to the tube under it (where air gets pulled in by the fan, for thermometer to read air temp and indeed it pulled air well).
i went fir a drive and looked at temp settings. Up till 24 degrees celcius, the air was cool, at 25 it was a little warm, at 26 warmer and by 27 it was hot. I think it’s working well?
fab

fabchef

hi gang, i know it's been a while since i reposted, but can someone get me the part number of the cabin temp sensor? every search i get is of the sensor that is located right in front of the rediator (which measures the outside temp), i can't find the one located just below the ignition key that measures the cabin temp.
thanks
fab

DennisMik

You want the cabin temperature. The number is 88790-12020. The list price at a dealer is $21.22. On-line prices are less but you have to add shipping and something that costs $15 ends up costing more with the shipping charges.

The one by the radiator is the ambient temperature sensor, part # 88790-22131.

fabchef

Dennis, thank you so much for the info. This part is like a unicorn...even the dealer had a hard time finding it. They managed to get it with the part number.

DennisMik

You are welcome.

The parts book is divided into sections and one of those sections is called Electrical. So that is the first section one would look at for things that use electricity. And your sensor was not in the Electrical section. There are 2 things that work against logical organization. 1) It takes many people to put together a parts book and unfortunately they don't all use the same guidelines. 2) Auto manufacturers refuse to name things logically, preventing normal people from finding them with the search function. This is standard auto industry practice, Toyota is not unique in this.

After not finding it in Electrical, I looked in the Air Conditioning section and it was there.

fabchef

Dennis, that’s interesting, I didn’t know that. It also doesn’t help by calling it a thermator. As well, the parts guy kept askkng me where it’s located, i told him just below the ignition key. When he pulled out the pic with the location and part number, it shows the location to be at the bottom left of the steering wheel. So odd!
even when i cross-referenced the current part that’s there now on the car, it tells me it’s from a toyota celica..🙄 odd...
the parts guy told me that it’s rare that this part fails.
the other thing i’m not too sure about it...how strung of a suction should there be from the tube that hooks into this sensor? When fan is on full blast, there is hardly any “pull” from it.
Thanks
fab

DennisMik

The parts supply system is strange. It may even be proof that we have been visited by beings from other plants.

When I search for the part number on different parts websites, it comes back with different names - sensor, in-car sensor, thermistor. I don't know why, it may be the revision/version of the parts listing. As for saying it is from a different make/model/year, again that may be because of the database being used. Small items that are not viewable will be used by car makers on many of their makes and models over many years. As long as it works, why change it. Sometimes searches will give you the first model it was used on.

As for the parts guy saying it was located in a different spot, perhaps he was not looking at a RX diagram. But every time you mention something about that place, I have less confidence in their ability.

As for the amount of air flow or suction that should be present, I have no idea. As long as there is some air flow, you will probably be ok.

fabchef

Hi guys. So i finally got the part in and attached it. Seems to be the same thing. My question is...
if i remove the tube that hooks into the sensor (that pulls in air past the sensor) and put fan speed on high, should there be a good amount of suction on it?
Right now, if i do that, with fan high, I don’t feel any air being pulled. Where does this flex tube connect to? Back of climate control panel?
thanks
fab