1. How can I keep the recirc mode on? The Owner Manual states it will stay on, as long as AC is in Auto mode. But no show.
2. What might me the problem if in spite of recirc mode being on, I still smell the nasty diesel or other fumes of vehicles in front?

1. How can I keep the recirc mode on? The Owner Manual states it will stay on, as long as AC is in Auto mode. But no show.
2. What might me the problem if in spite of recirc mode being on, I still smell the nasty diesel or other fumes of vehicles in front?

I've got 2500 miles on my H2 and haven't noticed a problem like that. It might be worth having the dealer check it out. Keep us posted.

I had the same problem, but try setting your AC first with the recirc on and holding in the "Auto" button in for about 3 seconds. This fixed the problem for me. But it will reset once you change your AC settings.

Tried Mike's tip to no avail. With recirc on, everytime I hit Auto, this will shut off the recirc mode.
No matter how short or how long I depress the Auto button.
Will have to live with it.
Now before driving away I look like an airline pilot. Before driving away I have to go through at least 5 "check" points:
1. Start engine.
2. Plug cell phone in hands free holder.
3. Depress recirc mode
4. Put safety belts on.
5. Lower drivers arm rest.
6. Speak to passengers if any.
7. Drive away.
With training this can be done in a few secs.

I may be wrong here but my understanding is that in the auto mode, the recirculation will not come on unless the inside of the vehicle is very hot. I think there is a sensor or something that turns it on automatically when it is needed for optimal cooling. I had the same question when I got my H2. I don't like the auto mode at all. I just run the AC on manual mode and control the temp by adjusting the fan...but you do have to press the recirculation button every time you start the H2. I wish that they would stay on all the time...but oh well. If there is one compaint I have with the H2 is the AC system...I think they could have done a better job.

In my case, the preference is reversed, I do not like "recycle air" function and always turns it off manually. In a hot car it blows loud and hard, I wish it does not come on automatically. Air polution is not a problem in my area, I want fresh air coming in. Only use recycle function when behind an old Mercedes or school bus. It is hard for auto makers to decide who where how why and when the aircon will be used.