want to disable automatic switching between recirc and outside air mode

You do know that in recirc, some fresh air is introduced into the system, just much less.

 

I'm glad it works for you, however it sounds like from all the other threads that you will manually have to adjust the air mixture, wish I had a better solution..

 

Perhaps I am lucky, and was able to do so via TS lite. I went the other way however, wanting to disable automatic Recirc. The only time it changes is if I do so manually, or activate the clean air feature (nothing but a timed Recirc, I believe)

It's been some time since I switched it, so I don't recall where the option is found.

EVO ? 2

 

So am I reading right that you're able to change the automatic recirc via TS lite?

 

I found it! It's a customization setting in TS. I'm going to my dealer to have this changed! But it reads as though this only works if A/C is activated.

Last Modified: 10-19-2012
Model Year: 2010
Title: INTRODUCTION: REPAIR INSTRUCTION: CUSTOMIZE PARAMETERS (2010 Prius)
Model: Prius
From: 200904
Doc ID: RM000000UZ0055X


... Excerpt...
DISPLAY (ITEM)- Air Inlet Mode
DEFAULT - Automatic
CONTENT - Function to shift from INLET mode to RECIRCULATION
mode when the A/C is turned on.
SETTING- Manual orAutomatic

 

I believe we have a winner! :-D

 

Here's the latest example of people dying from car exhaust and possibly why Toyota creates a default to outside air rather than letting you always leave it on inside air: http://www.sacbee.com/2013/04/10/5331026/mtv-cancels-buckwild-after-wva.html

 

TS lite = Techstream lite -> the official diagnostic software & Mongoose cable.

Your dealer has it :-D

 

Hate to rain on your parade, Asthmatic, but it seems that Toyota made a change to the A/C system software beginning 2012 (US) model year.
Service information now states that the Air Inlet Mode customization is only available for Korea and Mexico markets. See the attached file for details.
It may be worth having a tech connect a Techstream to your Prius and verify whether or not the Air Inlet Mode can be customized.

 

The normal recirculate mode allows in about 10% fresh air to prevent that.

 

Plan B might be to dig into how the system physically changes from recirculate to outside air and disable that valve/shutter actuator.

 

I agree with xs650.

asthmatic, you may want to just unplug the actuator which physically redirects the air so it remains in recirc all the time. This is not ideal, but would be the best bet for you.

 

Have you thought about just wearing a respirator while in the car? You may want to try something rated N95 and see if it helps. Now since your issue could be scent related, you might need an R95 rated mask as it's rated for oil based pollution. As far as a brand choice, with 3M you're more likely to get what you paid for. The masks are typically rated for around 8 hours of use so one could last you awhile depending on how much you drive.

 

I hate to tell you this but from someone who deals with this type of thing (software programming), it is not as simple as editing a computer program. There is a lot of overhead involved and probably more so than what I have to deal with. That one simple change could cost Toyota easily $50-200k. Now did you offer to pay Toyota any money for the new micro code? One person complaining about an issue does not make financial sense. Therefore it "can't be done". Just to give you an idea of the work, most places that have oversight on code are required to have a type of "Software Requirements Document" that would need to change. Then they are also required to write a "Software Test Plan" and also sometimes a "Software Test Procedure". Each of these documents must link back to the SRD. Then they are required to have a "Software Design Description" which tell what the code did and how it works - that will need to be modified. And that is just the front-end paperwork before they can even write one line of code. Then you have to make the change to the code and test that it actually does what you want. <- That is your "matter of editing a computer program". Next you have to perform the Software Test Procedure. This not only has to test the change you made but also make sure you did not screw up anything else that the software does. This literally can be as simple as a day of testing or several weeks. Then there is the possibility of government oversight. They may have to submit all paperwork and test results to an auditor. The auditor can then choose to accept the results as stated in the package or they may wish to witness the testing first hand. If that is the case, you have to start the testing process all over again (read more time and money). Finally the auditor signs off on the change and they can burn your one micro or send the software to the dealer to download - if that is even possible, not all microprocessors are able to be reprogrammed in the field.

The process is not as simple as editing a few lines of code when you understand the process that takes place. Believe me, we do everything in our power not to have to change code if at all possible.