4WD ECU Location

Ever since I opened up my front ADD and cleaned it out I've been getting the 4H blinking light. I've attempted to remove fuse, disconnect battery, and pound on it but it keeps blinking. I did the following per manual,:INSPECT 4 WHEEL DRIVE CONTROL SWITCH,
INSPECT DIFFERENTIAL VACUUM ACTUATOR
ASSEMBLY and now I'm stuck at step 3: INSPECT FOUR WHEEL DRIVE CONTROL ECU. I know I'm semi blind but I can't seem to locate it. I'm posting a pic of the passenger side compartment where the manual says it should be. Correct me if I'm wrong but am I looking for a black box that says 4WD ECU or is it something different?

 

Here is what the service manual says:

 

I'll go double check again. Does anyone have a live photo of what it might look like mounted on the vehicle?

 

This is what it looks like:

 

Yes that's what I've been looking for and I don't have that in my pictures. Could it be that it was stolen and I never realized it until I attempted to use my 4WD. Each time I switch to 4WD I don't hear any sounds, Clicks, or movement. Before I would hear the click sound but now nothing. Should I take a better picture? Does anyone have a picture of their 4WD ECU mounted?

 

Lay in the floorboard facing up, you'll see it.

 

@Charlie213 its over to the right towards the passenger door and straight up from where your glove box was (up high enough it's behind the upper dash)

Here is a pic for reference with the wires going to it.

 

I removed both wire harness from the 4WD ECU and one of the plugs has 2 slots with missing metal pieces. Looked inside and it doesn't seem like it makes contact with any metal. Could this be why I'm not getting any power to my font ADD? Does anyone have their ECU harness disconnected to confirm if it's normal or not?

 

Those two slots are unpopulated from the factory, no worries

 

Just because a plug has slots for wires it doesn't mean that they are used or populated. See the picture posted by another user you can see his doesn't have wires in that location either.

 

How am I suppose to check if I got the correct voltage if those 2 terminals are empty. The manual says terminals 1 &2 should have 10-14 volts when H2-H4 is selected?

 

Pin 1 & 2 are on the opposite end. Check this thread out, I've posted the ECU schematic and also something that should help you out in identifying pin numbers

https://www.tacomaworld.com/threads/4lo-signal.489735/#post-15073050

 

Thank you ill review it.

 

You're welcome! I've attached the full schematic for you. FYI pins 1 & 2 in connector B are for the transfer case actuator, not the ADD actuator.

 

Assuming everything leads back to my font ADD which everyone has mentioned is the main problem, am I suppose to get the older version or the newest version which I believe is part number 41400-35033. This site shows as
https://www.toyotapartsdeal.com/oem/toyota~actuator~assy~diffe~41400-35032.html
the correct one. Just want to make sure I get the correct version.

 

That I'm not sure on, you'd probably want to ask a dealer. Is the truck actually engaging 4hi but the green 4wd light keeps blinking or is it not even going into 4hi?

 

Before I opened up the front ADD to clean it the green 4WD light would come on and stay blinking only when I used the selector switch but would turn off after I shut vehicle off. Now the green 4wd light automatically comes regardless of position of knob. Certain times both 4WD and 4LO come on.

 

So I was referencing this post to find my ECU. I'll go ahead and add some pics to help others down the road.

1. Remove glove box.

2. Remove this piece


3. Which reveals this view



Hope that helps someone!

 

Did the ecu resolve your problem? I am having similar issues with my tacoma 07 2.7 Manuel I know for a fact my actuator on the t case and front diff work but I have a constant flashing 4 lo light on my dash and 4wd will not engage make noise nothing

 

It worked for a day then died again. I've been dragging my feet to fix it since.