Hello,

I have scoured the internet for all the details available for locating this sensor and plugging the white hose back up, however, I am unable to locate the sensor.

My issue is max cold or max heat so I followed the previous threads on this which led me to this sensor. I remove the driver lower knee panel, which I removed two screws and leave dangling by the OBDII plug. Left the knee airbag section in place. I can look up and see the white aspirator hose but cannot see a sensor to plug it in to.

This is on a 2008 is250 RWD AT.

Thank you for any feedback!


Looking up under the steering wheel after removing the knee panel. White aspirator hose but not able to locate sensor.

 

Next to the steering wheel right side. There is a little grill embedded in the panel. Do you see it? That's where it draws in air from. The whole thermisor assembly should be there. Also are you sure that's the hose? I remember correctly on my 2GS when I cleaned my thermistor it was a rubber hose. The one pictured looks like extra wire loom.

I could be wrong though. As I haven't been in that area in awhile.

 

Thanks for the response! I located the grille on the dash, however I will have to wait until tomorrow to address.

Am I correct I only taking off the lowest section of the dash beneath the steering wheel (contains OBDII plug) and leaving the knee bag section in place, correct?

I only ask because I have very limited space/visibility and I haven’t read much in the way of complaints or complexity with this.

 

The details here on this thread will get you where you need to be. Do it at your own discretion. I'm not responsible for anything going sideways. You can search for 2IS push start install though this one is probably the best one. Seems like the other threads the pictures are dead links. See picture below. You might still have to get under to release the tabs on the part itself.

https://www.clublexus.com/forums/is-...tton-swap.html

 

Your disclaimer made me nervous lol. Doesn't look like I should have to remove anything with the push start install, just the panel to the left. I think it will give me the increase visibility that should help. The reason why I thought this white tube was the culprit was due to a DIY on a .IS forum. I will work on this tonight and report back.

Thanks for the info!

 

This is what you'll be looking for. Find the HVAC hose that leads to it under the dash. So are you just cleaning it or replacing it? I would probably just clean it first. Then go from there. If anything clean it with CRC MAF Cleaner only, or equivalent.

 

I was thinking my lack of temperature control was due to this air hose not being connected the the cabin temp sensor. I only have max cold or max heat and nothing in between. Initial steps to check seemed easy enough, however it hasn't yielded a solution just yet. Hoping just plugging it back in does the trick.

Thanks,

 

So your saying you can't control fan speed? In the older gens Lexus line up they had a blower resistor the size of a cigarette pack. It controlled the fan speeds on the blower. When it went bad fan only blew on high speed, but you had to ground the blower to the chassis to bypass it.

The 2nd Gen IS has a AC amplifier. It controls pretty much the same as the resistor.

Look up threads on AC amplifier. If you find the hose yields the same results.

 

I can control the fan speed, but I can’t control the temp. At Lo you can get the a/c to be cold, but as soon as you turn the temp to 65 degrees, the temp shoots to the highest possible heat temp (regardless of what you set it at) and there is no adjusting it unless you turn the temp to Lo, which will kick on the coldest possibles temp. Hoping to look at this tomorrow. Thanks.

 

Ok,

Finally got a chance to take another look. I got the panel off the is next to the push button start and it gave me increase visibility. I took some pics, but was still unable to locate this sensor. Help please... is there a chance it was removed or am I in the wrong spot?

This is with the panel off. You can see the vent (lower circle) and an unconnected air hose, but there is no sensor laying around.

But there was this guy, but not sure where it’s supposed to go, but it’s to the left of the ignition and strapped to the same wires maybe?


This is a different look at that sensor that looks factory taped off

 

Don't think the sensor is there. Have you at the back of the panel and see if it is there? This is what the cabin temperature sensor looks like. The end of the white tube in your picture is supposed plug into the round opening of the sensor.

 

It looks like it's been removed. Are you the original owner?

 

I am not the original owner and we just purchased the rig from a private seller. This issue was mentioned. I have not seen the sensor anywhere. I would have figured even if the sensor was removed we would see the connector hanging out but the only item is the one that is taped up. Seems odd...

 

FWIW the Fusion App with Lexus PID add on pack allows you to see data from the cabin temperature sensor.
I'd have to look again but it was just called "Thermistor Sensor C°/F°"

This could tell you if its working but not getting air flow.

 

I take that back. Although it hovered at cabin temperature, it is not the cabin sensor. Behaves a lot like the cabin. It os not the seat temperature either unless it it was plugged into me bum at 98.8... Top left...



Disregard post...