Automatic Headlights

Earlier in this thread, there was a question and response regarding the possibility of tying in directly to the ECU. Just out of curiosity, do Hawkmoon and the other smart people here think it would be possible to do a pure OEM type install, using parts from Canada (or wherever)?

 

I am having issues with the lights turning on at dusk and staying on when the car is unattended outside.

I am going to try to move the accessory wire to an accessory supply. Right now both power and accessory are connected together to a constant power source.

 

Im having the same problem.. let me know what you think your going to do!!!

 

Tomorrow I am going to try to move the accessory wire to an accessory supply. Right now both power and accessory are connected together to a constant power source.

I will post my updates.

 

ok thanks.... I wonder why hawkmoon77 didn't have this problem??? Whats Different???

 

Maybe his car is always in the garage at dusk or at work in a parking garage.

I feel 90% confident that moving the accessory wire will fix the problem. I questioned connecting the two together from the start.

 

So, was this a stupid question? I mainly want to know if it's psosible to do the same thing using an OEM stalk that has the auto setting on it. I also had the impression from somewhere that the car already has at least 1 light sensor, so that if you could tie directly to the ECU, you wouldn't need to install another sensor. Is that totally wrong?

 

Hi - Yes, but Canada and other countries do have auto-on on some of their 2010 Prius models. That's why my first post was asking if it was possible to buy the OEM parts from a Canadian source, and install them on an American car, preferably with a direct tie-in to the ECU (assuming OEM has that tie-in). I thought that was what some of the early posts in this thread were alluding to. Your way obviously works fine, I just wondered if it was possible to do the same thing with all OEM parts and taking advantage of unused programming residing in the American ECU (if any). Thanks.

 

Here is an update:

Both my power and accessory power were connected to a constant power source. I did not read this paragraph all the way through.

Connecting both wires to accessory power fixes the issue. The lights no longer turn at dusk when the car is not running.

It does change the behavior of lighting on the car. By default the car leaves the lights on for 30 seconds after the ignition is turned off if its dark. This feature no longer works. When you turn the car off in the dark the lights will turn off at the same time.

I think the only way to fix this to connect red to constant power,
yellow to accessory and the violet wire to something like the overhead lights that dim when you walk away.

Another source that might exist for the violet wire is a connection to something that drives the head lights for 30 seconds. I doubt something like this exists.

 

so I think I might try that... I will just move my yellow wire to a accessory line.. and see what happens. By the way Judgeless what wire did you use for you accessory line?

 

Last time you asked I posted the info. This is from page 6.



The connectors are very close to the driver door sill. The red wire is contant power, the blue wire is accessory power. I used accessory power for my radar detector.

 

That does not work. That was the first thing I tried. It gives the same results as having both connected to accessory power. It would be nice to find a source with a delay like the overhead lights and connect that to the violet wire.

 

OK, I have discovered something VERY cool.

I had posted earlier that the light sensor wiring and ECU programming didn't appear to be present for the existing light sensor to be used for auto headlights. That is only HALF correct.

In fact, I discovered tonight that the ECU is indeed programmed for auto headlights - it is only missing the pulse signal from the sensor (one single wire from the light sensor to the ECU.)

In my previous post, I was thinking that the ECU was providing the pulse (which I did not find at the ECU), and using the "passive" sensor to somehow change the frequency of the pulse. This is not correct.

The light sensor actually provides the pulse. I took the pulse circuit that I'm going to be using for the NAV lockout disable, and connected it to the ECU input (pin 19 of L7), to "simulate" the light sensor signal. I then grounded pin 28 of L7, which is the "Auto" switch lead on the headlight stalk. A couple of adjustments to lower the pulse frequency (to simulate darkness), and VOILA! The headlights came on. Another adjustment back up, and a few seconds later, they shut off again!! SUCCESS!!
:whoo:

What this means:
1. The existing light sensor can be used; I need to find where the wire that is supposed to be coming from the sensor "stops". I suspect that this might be at pin 12 of LI1, which appears to be somewhere behind the upper glove box. (Hawkmoon, any more photos of this area that you happened to take when you had the dash apart? Both sides of this 12-pin connector are black.) Worst case, it is at pin 4 of connector I1, at the sensor itself (which would mean the upper dash needs to be removed to get to it...)

2. You can buy a Canada headlight stalk, and use its "Auto" switch position by adding a wire between pin 19 of L47 (at the headlight stalk connector) and pin 28 of L7 (at the ECU)

3. The Canada stalk can also (I assume) be ordered with the fog light switch, and you can wire that in to the existing fog relay circuit if you want to add fog lights. The fog light lead is already there from the headlight stalk to the ECU. You need a pin to come from the fog relay output (12V) at pin 8 of 2C, and run that through the firewall to your fog lights. No additional switch or relay required. (see the fog lights thread in the Technical Discussion forum - lots of options for fog lights.)

I'll say it again - This is very cool.

 

Oh yeah that's cool! Effin-A right that's cool! You da man!!! We're not worthy... :hail:

 

I tried digging through that thread but it was so long I probably missed your info. Do you have the info on where to buy the stalk, and of course the part #? Thanks.