Hi Guys,

Just picked up a 2008 TL, White, 92K miles. Cherry, really nice car. Coming from a trusty 1997 CL that I drove from 2000-2016, put 270K on her, so she was at 301K, (and she wasn't even dead when I traded her in), pretty excellent car.

Here's the thing. I live in Phoenix. It's flippin' hot. I really wanted a good AC system in my new ride, after all these years. The one in this TL ... is leaving a lot to be desired. To be very clear, I'm talking about what happens in AUTO mode. If I manually crank fan up to 7, it does pretty good ... but 'auto'? It SUCKS.

The gist of things is ... it feels like the so-called 'temperature gauge' is really just a 'fan speed gauge'. It's like, on 'Lo' (I think that's just under 58F iirc), the fan comes on at about 5 speed (out of 7 total speeds iirc). From 58 to 60, it runs at 4 speed. At 60-70 it runs at 3 speed. At 70-76 it runs at 2 speed. Understand ... I'm sometimes getting into my 120F (interior) car, in 110F weather ...

Here's the main points:
1) I have NEVER seen 'Auto' mode kick my fans into full bore, ever. Even with Auto Temp set at 60F, in a 120F car, not even after some driving time has passed where it's had time to 'get cold', it still won't 'blast'. Only 'Lo' will really blast, and even THEN, it's still never even at the highest fan speed. I HAVE to go to manual to get the highest speed.
2) I don't think I've ever had the fan speed change 'of it's own accord'. So if I get into my garaged car in the AM, and inside it's probably 90F, outside it's 108F, and my Auto climate control is set to 76F, it'll run at 2 fan speed all the way. If I set it to 72F (which is a VERY tough temp to get the interior of a running vehicle to ... in 110F outside weather) ... at NO TIME during my drive to work, will my AC 'blast' air into the cabin, nor will it ever 'slow down' as if it's 'reaching' that temp. It more like the car thinks 'Well, 72F, that means 2 fan speed' ... PERIOD. Now, I push temp gauge down to 68F, it will kick up to 3 fan speed ... but it'll never waver from that.

I really is like the temp in the car does not matter. The so-called 'auto temperature' is just a fancy way of saying 'fan speed'.

My old 1997 TL worked TOTALLY different. I get in my 95F car in the garage in the AM, in Auto mode, with temp set to 72F, it would barely blow air for the first 1 min or so ... then once the air got cold, it would BLAST awesomely freezing air for about 5 mins ... then slowly taper down as the temp approached 72F. If I set the temp to 68F, it would BLAST the whole way to work cause it couldn't GET the car that cold. Point being, that car SENSED the temperature inside the vehicle, and reacted to try to get the cabin temp to the level you're requesting ... NOW.

Again ... the TL seems to act absolutely NOTHING like that. Am I missing something? Some 'setting' somewhere? Is a fuse blown or something? Why does it act like this? For the life of me I cannot get a sense that the car actually 'knows' ... what the temp is inside the car. Period.

TIA!!!

 

mine fan speed on auto varies between out side ambien air, if out side reading 100 the fan will blow at high speed then gradually reduce the fan speed. may be you need to clean out the cabin temp sensor (highly doubt) I living in Houston TX and temp has hover around 100 lately.

 

It certainly sounds like your AC system is not working as it should. Granted I have a different model (4G) but I suspect they would work very similarly. On AUTO, the fan speed depends on what the AC temp is set to, what the inside cabin temp is, what the outside air temp is and where the sun is (using GPS). There may be other factors as well. Depending on these, the fan speed will change. So, at first when teh cabin is hot, there is lots of fan but it slows down as the cabin temp decreases.

 

Yup that how my ac works, if you drive in the sun direction the fan will blow harder and if you are in shade the fan blow slower. Check your interior temp sensor.