Ok, here is my latest 2005 acura tl problem. Yesterday when driving for about an hour on the highway I started to get smoke/steam through my center vent on the dash. I immediately turned the AC off and it stopped. It stopped so fast that it was hard to tell if it was smoke or steam. My temp gauge wasn't up or anything, I pulled over shortly after and popped the hood. The radiator looked fine and I didn't smell or see leaking coolant. My tl has 90000 miles on it. Any idea what the problem is? Thanks in advanced.

 

My 2nd gen TL does this, as did my sister's 6th gen Accord, as did my father's Accords he had in the early 90s.

It is just harmless moisture. When it first happened to me I thought it was exhaust so I shut the A/C off.

Apparently it's quite common with Hondas.

 

If you get steam/smoke when the AC is on, it can be a sign your heater core is leaking. I have seen it on two vehicles I have owned over the years. My wife's Equinox was doing this as well as frosting the center vents. However on the Equinox we could smell the coolant in the air. No "leaks" anywhere, just the sweet scent when the A/C was on along with the condensation on the center vents.

 

This happened to me recently. It may simply be low on R-134, causing the evaporater to ice up, then fan blows some water vapor out the vents. When was the last time you changed your cabin filter?

 

I had a diagnostic test done on the ac in June and they didn't say it was low but I haven't changed the cabin filter in about 2 years/ 30000 miles.

 

What type of diagnostic test did they perform? Also if you have a leak (hoping I don't ), in the time that has passed since June, you may well be low now.
You should replace the cabin filter. It's simple to do and not expensive. It's not going to fix your issue but good general maintenance. I do all three of our cars once a year - cabin and engine filters.

 

It's normal when the atmospheric conditions are just right. Usually nothing to worry about. If you can't smell anything I wouldn't worry about it. Mine has done it a few times since the car was new and I've never had an issue with the system.