Confirm Light Sensor in IV or below?

Isn't that the solar heat gain sensor?

 

Why not cover it, turn on your headlights in a bright area, and see if the dash panel lights dim? Reverse and see if they brighten. I believe that controls it, based on another post.

 

Post deleted, bad information. Sorry

 

At first I assumed that's what it was, but the owner's manual says it for the automatic headlights (which we don't have in the U.S.)

 

Thanks stream that's what I was thinking also. I don't have my new Prius yet, can you confirm that the U.S. Prius (II throuth V) does not have true auto on/off headlights that turn on and off depending on ambient light? I have the impression that what Toyota calls auto headlights on our cars just come on when you start the car and go off 30 seconds (programmable) after you shut it down.

I am presently driving an '09 Corolla loaner car, it has the button on the dash too. It doesn't have auto headlights but it does have DTRLs and the button seem to make them dimmer or brighter depending on ambient light, I don't know why they did that.

 

Correct--no auto on/off headlights in U.S., and there is auto headlight turn off (like follow me home lights on other cars I've owned) a certain time period after you turn the car off and open the driver's door (it's a variable time limit that can be changed by the dealer).

 

This is a feature that I really would like to add to my IV. If anyone has any idea on how to make this work please post them.


I have not owned a car with out auto lights in 15 years. Why would they leave such a basic feature out?

 

Hi Judgeless:

I am looking forward to my 2010 Toyota Prius arriving soon and I found out that the Canadian Models do have Automatic Lights!! I have had this feature on many other cars I have owned and it is a great feature.

That being said, here is a link with info from forum member Hawkmoon77 about his venture into creating Auto Headlights:

http://priuschat.com/forums/gen-iii...modifications/64812-automatic-headlights.html

Hopefully this is of some help.

Edward
Marystown, Newfoundland
Canada

 

I have a IV (with no options) and was also curious about the "button" on the dash near the windshield. Here's some information from the Air Conditioning section of the New Car Features that I downloaded from the TIS that may explain it:

Compressor Speed Control
The air conditioning amplifier assembly calculates the target speed of the compressor based on the target evaporator temperature (which is calculated by the temperature control switch, room temperature sensor, ambient temperature sensor, and automatic light control sensor) and the actual evaporator temperature that is detected by the evaporator temperature sensor in order to control the compressor speed.

The air conditioning amplifier assembly calculates the target evaporator temperature, which includes corrections based on the temperature control switch, room temperature sensor, ambient temperature sensor, automatic light control sensor, and evaporator temperature sensor. Accordingly, the air conditioning amplifier assembly controls the compressor speed to an extent that would not inhibit the proper cooling performance or defogging performance.

Apparently, the sensor on the dash is used as part of the neural network that controls the air conditioning. Yes, I said neural network. That's also mentioned elsewhere in the section on air conditioning. Pretty damn advanced, if I do say so myself.

 

Found it!

(b) Neural Network Control

(1) Previously, in automatic air conditioning systems without neural network control, the air conditioning amplifier determined the required outlet air temperature and blower air volume in accordance with the calculation formula that has been obtained based on information received from the sensors. However, because the senses of a person are rather complex, a given temperature is sensed differently, depending on the environment in which the person is situated. For example, a given amount of solar radiation can feel comfortably warm in a cold climate, or extremely uncomfortable in a hot climate. Therefore, as a technique for effecting a higher level of control, a neural network has been adopted in the automatic air conditioning system. With this technique, the data that has been collected under varying environmental conditions is stored in the air conditioning amplifier. The air conditioning amplifier can then effect control to provide enhanced air conditioning comfort.

(2) The neural network control consists of neurons in the input layer, intermediate layer, and output layer. The input layer neurons process the input data of the ambient temperature, the amount of sunlight, and the room temperature based on the outputs of the switches and sensors, and output them to the intermediate layer neurons. Based on this data, the intermediate layer neurons adjust the strength of the links among the neurons. The sum of these is then calculated by the output layer neurons in the form of the required outlet temperature, solar correction, target airflow volume, and outlet mode control volume. Accordingly, the air conditioning amplifier controls the servo motors and blower with fan motor sub-assembly in accordance with the control volumes that have been calculated by the neural network control.

 

Wow! thanks for posting that RRxing, the system is rather more complex than I had imagined.

 

Yes--fog light switch. No--auto headlight position.

 

Now, if someone has the time, patience, and inclination to download the electrical wiring diagrams for the AC, we can probably put this to rest. Until then, this is the only diagram I have:

 

Do you think we could at least utilize the sensor to avoid having to locate a second sensor somewhere else?