We've only had the car since last Friday, so there are plenty of things we don't yet know. However, this one seems strange: my wife was sitting in the back seat with the baby, and the vents were blowing hot air back there even though the A/C was on and blowing cool air through the front seat vents.

I played with it a bit, and I think I've got it tied back to the ECO mode: when ECO is on, it blows hot air to the back seat; when ECO is off, both front and back get ample flow of cooled air.

Has that happened to anyone else, or is that a bug we need to have the dealership address?

Definitely a bug. You should be getting cold air all around. We had some 100 degree days with high humidity this summer, and the A/C always kept the car cool, front and back. And I always kept it in ECO mode.

get it checked out...i keep my my TCH a/c set at 74 in eco mode and get cold air from all vents

Hmmm. Good to know, thanks. I'm taking it in this Thursday to have them buff out a couple minor scratches incurred during transit, and to fix some air bubbles in the tint. I'll have them check this out, too.

Will keep you posted on what they find. Stay tuned...

I am pretty sure that the rear air is set at the passengers temp, so if the passengers temp is set too high this could happen.

Good thought. Didn't think of that possibility.

I finally got around to leaving the car with Toyota Service yesterday. They replaced the tint all around -- did a sloppy job the first time -- and looked into this front / back cold / hot differential thing.

They "adjusted a vacuum hose" that supposedly fixed it. It seemed to work correctly on the drive home yesterday afternoon, but I think it was back to its old tricks this morning. Haven't had enough time to really play with it, though.

FL07THC is correct, btw. When you're in dual mode, the passenger temp controls both the passenger side and the backseat. That's one of the things I'd eliminated, though.

It took a few minutes to convince the service guy that there actually was a problem. I finally boiled it down to this: if you're not in Dual mode, then no matter what the temperature gauge says, the back vents should be blowing air of approximately the same temperature as the front vents...right?

My original post said that it seemed tied to ECO. Now I'm not so sure. I also tried to eliminate the outside / recirculate thing, A/C vs. non-A/C, and various temperature ranges. It's all been inconclusive.

If the temperature is set anything much under 70 with the AC on, then both front and back blow cool air -- as expected. Anything much over 80 and both blow warm air -- again, as expected. Problem is, we tend to live in the mid-70s...and that's where the front will blow cool while the back pumps heat.

Hmmm. Doesn't make sense, does it? If it was a mechanical blockage or something, you'd expect the back vents to NEVER blow cold air...but they do, just not at quite the right time. The vacuum hose idea sounded plausible to me...but anybody else got ideas?

Air Flow Diagram from manual

Nice to know

I'm recycling an old thread of mine from months ago because we're still having this problem....need to know if anybody else's is doing this.

I've had my TCH into the shop three times now at two different dealers, and I've talked directly to the A/C techs twice. The problem hasn't changed: when both sides are set to the same temperature (with Dual on or off, doesn't seem to matter), the air blowing to the backseat is considerably warmer than what you get out of the front vents -- even the vents on the passenger side.

I've been able to demonstrate this thoroughly for the service managers and the techs, and they've run all the diagnostics -- including performing a reboot of the A/C system. It's not fixed, but they're saying it's working as designed.

So...I need your help to determine if this is a design issue that everybody experiences (even if not everybody cares), or if it's just my car. If you get a couple minutes and wish to humour me, please try this:

• Set the driver's side temp to 75-ish;
• Turn off Dual, or set the passenger side to match the driver's side;
• ECO on or off, doesn't seem to matter on mine;
• A/C on or off, doesn't seem to matter on mine;
• ReCirc on or off, doesn't seem to matter on mine;
• Set the vents to blow up through the console (not heat towards the floor);
• Now crank up the fan to the 4th or 5th setting;
• Finally, check the temperature of the air coming out of the vents in front against what blows into the backseat from the armrest riser.

Is it the same temperature? Or is the backseat notably hotter than the front seat?

If I crank it all the way up into the 80s, it blows hot air everywhere. Likewise if I turn it down into the sub-70 range, it blows cold air everywhere -- unless it's colder than that outside, of course. It's only in the temperate range -- where, of course, we usually keep it set -- that the temperature differential occurs. Do you see it too?

Lemme know. I've been through the manual and have tried every permutation of the controls, no avail. The obvious workaround is to simply use Dual and keep the passenger side (which includes the backseat) 3-5 degrees lower than the driver's side. But that's a pain, and it's illogical to boot.

My wife's about to blow a gasket on this one. That'd be fine if it's really just our car. But if it's a design flaw that affects everyone....well, then we're all just blowing hot air, right?

Thanks,
B.c.