04 CTT A/C Controls as one not two zone...help?

[kimichi]

The two zone A/C was working fine, the driver side control air level on its side and as so the pass. side. I went to lunch and when I came back the drivers controls would also control the pass. side air level and the other way around.

Now, I can't figure out what happened and how to get it to go back so driver and pass. can control their own air level.

Auto A/C makes the two zones blow as one but after turning auto off, you still can't control either zones.

Any ideas?

Thanks

Edited March 26, 2013 by kimichi

[bigbuzuki]

Is there a "mono" indication lit up in the a/c display? Hold the "Auto" button for a few seconds until the "mono" extinguishes, at which time you should have restored individual control.

[kimichi]

Yes, I tried that but nothing changed.

[deilenberger]

Just a thought - the individual settings only are for the temperature. The fan speed is always controlled in a mono-mode (since there is only one fan.) When you speak of "air-level" are you referring to the fan speed control? If so - it's working exactly like it's supposed to.

[kimichi]

Yes, air speed but I was able to control air speed and temp on either side at different levels as a two zone. Now, its controlling as one. I have always been able to control either zone. Ex.-Driver 65temp 3bar air speed, Pass. 68temp 5 bar air speed. Any level or temp driver or pass. wants.Now, both same temp and air speed no matter which controls you use, driver or pass.

[wvicary]

There is only one fan so the fan speed will be the same for both the passenger and drivers side, only the temperature setting can be altered.

[kimichi]

That's weird. It was always able to adjust the temp and fan speed at different levels at the same time, it was great. Wondering....why would they put two controllers for the fan speeds if you couldn't individually control them like the temp? I thought that's why it's called two zone and two buttons to control temp and fan speed on either side. I wish it would good back.

[bigbuzuki]

Kimichi.

You are correct stating that you were able to separately adjust both the temp and fan speed independently from either drivers or passengers side.

Althought there is only one fan in a 2 zone system, independant airflow control is achieved by the system also modulating the volume air flap servos to regulate the commanded air flow required by either party if the demand is different.

My 4 zone system operates likes this and the 2 zone mode of operation would not be any different.

Therefore you are correct in suspecting a fault in your system, obtaining fault codes should be your next step since it is not finger trouble on your part.

At a guess it sounds like your controller has suffered a glitch.

Edited March 28, 2013 by bigbuzuki

[mudman2]

controller toast, again a common 04 problem

[kimichi]

That's what I was thinking maybe a switch or fuse. Thanks everyone for the help. Aloha!

[deilenberger]

There is only one fan so the fan speed will be the same for both the passenger and drivers side, only the temperature setting can be altered.

+1 - but it depends on the HVAC system installed.

Open your owners manual to page 148. "Automatically Controlled Two-Zone Air Conditioning"

Note that the fan buttons are BOTH labeled "G". On page 149 it says:

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"Setting air quantity"

> Push button G up or down to adjust the air quantity.

The selected air quantity is shown in a bar display on the display above the button.

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There is one fan on the two-zone system and no separate air volume flaps. The control "G" - which has two buttons labeled G controls the single fan speed and the air quantity. I'd suggest anyone doubting that (who has a 2-zone system) go out to their truck and try it. The temperature controls are labeled "G" and "O" - these are separate left/right temperature controls (unless set in MONO mode.)

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On page 152 under "Automatically Controlled Four-Zone Air Conditioning"

The fan controls are labeled G and S - these are separate quantity controls, and there are even separate function buttons for left/right for things such as air direction/outlets under the slide down door. The instructions make reference to controlling the left and right side individually on page 155:

Setting air quantity

The air quantity can be selected individually for each of the four air-conditioned areas.

> Push button for air quantity up or down.

Button G: LEFT air-conditioned area at the front or rear.

Button S: RIGHT air-conditioned area at the front or rear.

The selected air quantity is shown in a bar display on the display above the button.

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Your 2-zone system only has one air-control. That's how it is, and how it was. Unless you have a 4 zone system.

Your mileage isn't likely to vary..