Avensis t25 climate control problem.

[Rob1234]

Hello!

I'm about to buy a Toyota avensis 2004 but the climate control is malfunctioning.

It only blows hot at the windshield at all times. You can't change temperature or direction.

If I press auto it just turns off the fan.

Temp and direction on the display works but nothing is happening.

Could it be just the climate control unit that needs replacing or does the whole dash need to come out?

[Stivino]

What style of controls does it have, digital or rotary?

[Rob1234]

6 minutes ago, Stivino said:

What style of controls does it have, digital or rotary?

Digital. 

Like this.

[Stivino]

I have a similar set up in mine and I have found the the OFF button sometimes sticks.  Every now and again I give it a spray with electrical contact spray just to help it.

It might be worth checking that none of the buttons are sticking, especially the  “auto” button and the demist button.

[Rob1234]

7 minutes ago, Stivino said:

I have a similar set up in mine and I have found the the OFF button sometimes sticks.  Every now and again I give it a spray with electrical contact spray just to help it.

It might be worth checking that none of the buttons are sticking, especially the  “auto” button and the demist button.

Both the auto button and off button works and registers.

If I press the auto button it just lowers the fan speed as low as it can go.

[Stivino]

I don’t want to insult your intelligence by stating the obvious but, I would make sure it’s not in dual zone mode and that it’s not on auto.

Any more than that and I’m sorry but without seeing it I couldn’t suggest anything else.

[Rob1234]

3 minutes ago, Stivino said:

I don’t want to insult your intelligence by stating the obvious but, I would make sure it’s not in dual zone mode and that it’s not on auto.

Any more than that and I’m sorry but without seeing it I couldn’t suggest anything else.

Tried both dual and non dual, auto and non auto, full fan on feet and full on dash wents. Nothing works.

only thing changing is the fan speed, nothing else.

Thank you for your time!

[pcallo]

There is a fault in the climate control system. It's possible that the issue could be with the blend door actuator or control cables, which are responsible for directing the air to the different vents and regulating the temperature.

Another potential cause could be a malfunctioning HVAC (heating, ventilation, and air conditioning) control module, which is responsible for controlling the operation of the climate control system. If the control module is not working properly, it may not be able to receive or send the correct signals to the various components of the climate control system. In other words, diagnostics may be the only solution.

[paul9]

There is a reset/diagnosis procedure on the AC unit. This video is all I could find quickly, although there are definitely better videos and guides for it. The display should bring up any trouble codes stored in the AC system, after testing the motors and flap positioning.

 

[Stivino]

2 hours ago, paul9 said:

There is a reset/diagnosis procedure on the AC unit.

🙆 I forgot all about that and I've used it on mine. 

[Rob1234]

Thanks for all suggestions! 

I bought the car yesterday! Really cheap because of this fault. 

I will be trying some stuff later today. 

[Stivino]

Good luck and, please let us know how you get on.

[paul9]

I miss my Avensis.

[Rob1234]

Okay so today I read fault codes: 13, 21, 24, 31, 33, 36, 41, 43, 46. Sooo basically everyone 🥲

I checked every fuse related to heater and aircon. No burned ones. I also tried disconnecting the Battery for half an hour but it didn't help.

I ordered the control unit (the one with buttons and display on it) off of eBay so I will try that next I think.

[Chelyuskin]

It's likely the airmix motors under the dash.

They can be reached without dismantling the dash from the driver's side footwell and glovebox area. They consist of a simple electric motor, gear set and a resistance track which wears out, causing the unit to hunt and eventually stick in a random position.

I managed to repair mine by cleaning the track and regreasing it. New ones are quite expensive with aftermarket alternatives not available.

[Rob1234]

2 hours ago, Chelyuskin said:

It's likely the airmix motors under the dash.

They can be reached without dismantling the dash from the driver's side footwell and glovebox area. They consist of a simple electric motor, gear set and a resistance track which wears out, causing the unit to hunt and eventually stick in a random position.

I managed to repair mine by cleaning the track and regreasing it. New ones are quite expensive with aftermarket alternatives not available.

I thought about that too but isn't it unlikely everyone is broken at the same time?

I found a workshop manual that shows where to apply 12v to test them so I will do that this weekend.

[Chelyuskin]

There should be 4 of them, 2 for temperature (separate for driver and passanger), one for mode (where to blow) and one for recurculation (from where to suck).

Often times, these start hunting as early as 80,000 miles making a buzzing sound. People just ignore it, but the hunting causes the resistor track to wear out, rendering the unit useless. Replacements are 200+ online and 400+ pounds from Toyota dealerships.

I'm not saying it can't be a controller problem or something else, but the airmix valves are usually the culprit.

 

[Rob1234]

1 hour ago, Chelyuskin said:

There should be 4 of them, 2 for temperature (separate for driver and passanger), one for mode (where to blow) and one for recurculation (from where to suck).

Often times, these start hunting as early as 80,000 miles making a buzzing sound. People just ignore it, but the hunting causes the resistor track to wear out, rendering the unit useless. Replacements are 200+ online and 400+ pounds from Toyota dealerships.

I'm not saying it can't be a controller problem or something else, but the airmix valves are usually the culprit.

 

Okay! Thank you! 

I will check them!

[Rob1234]

I finally fixed the issue! I changed the climate panel. No differance.

I then found a repair manual online with all pinouts and I started to check all ground and 12v pins but something was not right.

The radio has three plus and the climate panel has two. And when I put everything back together I noticed the radio and the climate panel

hade one plug that was physically identical! So I tried changing them around and now EVERYTHING works perfectly and AC blows ice cold!