2016 fog light harness.

One could dig that wire out to the ecu and trigger the fogs on and off by adding the relay and wiring, but what if the ecu went out during the 36/36,000 warranty, and they looked in there and saw that mod. Roll the dice on whether they would say you caused the ecu to blow and it was not covered. I think I'll just go with a separate circuit and leave well enough alone for warranty purposes.

 

If you google "bfg fog" you can see some downloads of pdfs of where Toyota has fog light mod installations on other vehicles that tie into the bfg pin on the ecu which activates the fogs properly with low/ high beam selection. I have decided to try to do this on the 2016 Taco to make it like factory except use a dash switch to turn on instead of the light stalk. With fog relay and factory harness to the fogs all else will be stock.Do you have any info on ecu location pictures or anything that might help in this ? Thanks.

 

I'll dump what I have for you, as I basically want to do exactly what you're doing. Be sure to write up a good how-to if I don't beat you to it.

Anyways I can't find a definite location for the ECU, and I just scrolled through about 6,000 pages of the 11,000 page service manual. My eyes feel like they are going to fall out.

That may not matter though, as I found this simplified fog schematic:

Looks to me like you don't even need to touch the ECU if you can get to the driver's side junction block, which is right behind where you want to put your dash button.

My other-other wiring diagram backs this up:


And the junction block connector looks like this:

pin 27 is what triggers the fog relay. Remember, this diagram is facing IN to the connector, not looking at the back of it. So imagine you un-clicked the connector and were looking down the holes, not looking at the wires going into the back.

So I think if you just "steal" pin 27 away from the ECU and to your switch, you can totally bypass the ECU and not have to worry about frying anything.

 

However by using the ecu fogs will go off with low beams which is an inspection requirement here and I have been hassled with it in the past. That's why I don't want to bypass it. I could just pull the low beam 12V line to another relay to drive the main fog relay more simply guess.

 

Exactly why I made my own harness and wired it to my own switch and got the power for the switch on the ignition fuse and took the power for the fogs straight off the battery!

 

ahhhh I totally forgot about that

Well crap. Let me keep looking, my best guess right now is that the ECU is gonna be behind the glovebox and you get to it in a similar manner to replacing the cabin filter.

 

Scratch that, I'm wrong. Also I was under the dash and had my grubby mitts ON THE ECU just a moment ago and I was like "wtf is this, I dunno..."


It's actually a part of that "junction box" so my intercept idea is sort of pointless anyways.

 

That won't turn them off when you select high beams.
I will fail, and I am sure all states have same rules, state inspection at Toyota with that method unless I remove the lights each time which I am not going to do. You can pull a line off low beams to drive a relay which would correct it but would be far from factory also. Toyota wouldn't build it that way if it weren't a requirement.

 

Shit, if I had the dealer busting my balls about that at inspection time and they wouldn't let me get away with just pulling the fuse and a "dunno, lol inoperable lights designed for off road use only, wink wink" I might try going to a different place.

I understand that it's an inspection requirement and I understand why- but I've never ever thought "it sure would be great if I could run fogs and high beams at the same time" though, so I honestly would never try it. I also am not a dickhead who would think "gee, this public road (and/or random people coming in the other direction) could really use my light bar" unless it was like, road emergency conditions or in the middle of nowhere.

 

There have been inspection stations here that have lost their shingle for a month. They send around undercover inspectors to test. It's not the dealer being anine, it's the loss of the shingle they worry about.

 

good info.