I've had my 09' FEH for about a year now, thought I understood the heating controls, although I still prefer the old school dials over digital I've gotten used to it. Last weekend after some 5 hour Thanksgiving holiday drivinig I'm now confused by the controls.
I was driving alone, only had the drivers side temp set...had to keep constantly changing the temp up or down a degree..I like some air blowing while I drive and it kept blowing really hot or cold air so I was always flicking it a degree up or down to control it. While changing a radio station I reached over and noticed the passanger side dash vent was blowing HOT air, I mean really hot, like the dial was set to 90 and there was alot of air coming out, not just a trickle like it was sneaking past a flapper. I didn't think that side was suppose to be "on" if the temp didn't readout on the dash display?
I ended up keeping that side on but in the low 60's just to keep some reasonable air coming out if it, and it kept me more comfy on the drivers side....but now I'm confused...thought the sides were independent and if you didn't press the temp dial for the pass side it was just "off"????

 

Sounds like a warranty trip to your dealer might be in order...there are a few known issues with the temp control doors and other components in the FEH's...

 

Same happened to me on my '08... turned out to be the blend door motor. Dealer replaced under warranty. Incidentally, this fixed the dreaded clicking hard-drive type noise that was coming from behind the dash.

Darren

 

Hmmmm, I hadn't thought it was a serious issue...just a glitch with the system but thanks for the heads up! Guess it's time for them to look at my drivers seat also then...some weird clicking feeling in it when my weight shifts in a turn etc..

 

First, for there to be airflow, outflow, from both the driver and passenger side all that is needed is forward motion of the vehicle and the system in FRESH incoming airflow. Second, anytime the driver's side is "on" so is the passenger side.

All the separate temperature control setting, passenger side setting, allows you to do is independently control the temperature of the system outflow air on the passenger side vs the driver side. The same blower speed, airflow volume, is used for both, only the temperature of the outflow will differ.

And speaking of "differ" that will be true only within a certain range. Remember that the base "target" of the system is to satisfy the average cabin temperature using the IAT, Internal (passenger cabin) Air Temperature sensor. Set the driver temperature control to the "hot" side and the passenger temperature will "closely" follow. The two settings cannot be so diverse, different, that the base HVAC controls cannot work.

Oh, many of these automatic climate control systems will automatically switch into "cooling" mode once the cabin becomes heated to within a few degrees of setpoint. On a cold day, or really COLD night, the resulting coolish and dry airflow toward the face and upper body can be, will be, somewhat discomforting. So it is adviseable that you overcome this by manually switching the system back into "heating" mode, footwell outflow. Toyota even provides a C-best setting to prevent the automatic switch to cooling.

 

I have the same issue as the OP on my 2009 MMH. I'll be curious to see the reponse of the dealer when you bring it in. I hate bringing it in and leaving it for a day and being told everything is normal when I pick it up.

We manually close the vents. Or as one poster had done, we manually select the floor heat control and the temp fluctuations are limited to that outlet.

The MMH seems to blow hot or cold air - nothing in between. I have to set the passenger side or it blows hot air.

My Honda Odyssey was easy - just set it and forget it.

Dave