4wd System Operation & Help Thread

So, what happens when you turn the switch to 4HI?
Nothing? Nothing at all?

If so, I’d inspect the switch.
But then again, you say the test checked out?
So if the switch was bad, your 2-4 numbers would be off.

@Dm93 what would happen if the TM1 failed to energize and and not power the motor?
Would we get flashing lights warning us of a system malfunction?

 

Ok after I got the add back in and in the correct position ( fork towards passenger side of truck) I was still not getting any movement at the 4wd actuator and a blinking light. Thought it could be the timing since I was already in there fiddle fucking. Pulled just the cover and it appeared to be right so pulled this motor apart again cleaned the brushes that were not very dirty then hot wired to ensure it worked. Maybe just spinning it on the bench brought life back to it. Reinstalled and everything works perfect. Super pumped.

thabk all you guys so much. Awesome thread. Love working through problems not just brining it to the dealer who does the same thing….

new to my Tacoma and Tacoma world this place is great and this truck is a tank! Especially now with all my gears.
Cheers!

 

The lights would still flash if the motor wasn't getting power or was getting power but not moving.

Srry I haven't replied, I've been feeling like crap the past few days but looks like @TnShooter has got you sorted.

 

Welcome to the forum! Aren't you glad you stopped by? Nice to follow it and see it come to a positive resolution. What's great here is that even though my system is working fine, by following every one of these sessions (there's been a bunch of good ones lately) when an issue comes up it allows us to become a little more familiar with how it works as well as maybe why it doesn't.

 

it must have been the case that the motor wasn’t turning. Then just hot wiring it on the bench resurrected it. Now I’m driving all over switches in and out of 2H 4h and 4l without any problems. Do get a pretty big clunk 4h - 2H and seems to prefer being in gear and moving to make the change not sure if anyone else has seen that?

 

I’m super pumped! And It’s honestly pretty simple once one gets past all the jargon. This thread has so much info it’s hard to digest when you come in naked. Basically first thing anyone should do is back probe the 4wd ecu and figure out where your problem is. Go from there quit firing from the hip. The only thing I found confusing was what pins correspond to what functions on the actuators…. I probably coulda got wired each motor (1-2 pins on each actuator) got them spinning and solved the whole problem without pulling anything off the truck…..

 

Pretty common as the driveline tends to bind up on hard surfaces in 4wd especially when turning.

Yea I guess I need to clarify that a bit better, I'll see what I can do when I get to feeling better and update the first post.

 

@Dm93 you’re a legend! Thank you! Hope you feel better soon!

 

At rest, mine switches into H4 from H2 fairly smoothly every time with only some occasional slight hesitation/delay. It's definitely sends you a "mechanical" message/signal when it makes the switch. (I kind of like it honestly) H4 to L4 makes a little more noise and is a little more clunky. L4 back to H4 or H2 is accompanied by a little more "drama" with a metallic-sounding "clunk". If you exercise it a couple of more times: less so. At speed on a H2 to H4 change (or back), I can feel it slightly, but all I ever really hear is the relay or whatever clicking over there behind the glove box door.

 

Still trying to figure out my problem before taking it to a mechanic. A while ago my rear driveshaft went out. Had to send out the driveshaft for a month, in the meantime drove it in 4Hi off the front wheels (only vehicle at the time). After we put in my rear driveshaft, I messed up and didn’t re-engage my 4wd for a little over a year. When I went to use 4wd one day, no movement in forward or reverse.

I’m basically trying to find out if you folks think my transfer case is bad. If it is, I’ll just buy a new one and put it in. If someone else thinks it might be something else, then let me know. Thanks in advance fellas.

 

I’d removed the front driveshaft and try it in 4WD.
Transfer cases are expensive, I’d like to know where the problem is 1st.

 

Disconnect front driveshaft, put it in 4wd, and then see if my truck will move only off the rear wheels, correct? If it does happen to move, what would that narrow down?

 

Yeah, but you aren’t trying to drive the truck.
You need to see if it’s the front differential or the transfer case.
I’d put the front up on jack stand. Chock the rear tires for safety.
Put the e-brake on. Place truck in NEUTRAL and spin the front tires by hand.
If the front wheels won’t spin, the problem is in the differential.

If they do spin. It’s in the transfer case.
To verify, just do the same procedure for the rear wheels.

Remember, chock the wheels that are on the ground. For safety.

 

got it, thanks for clearing that up for me. Although………..I’m 0-2 right now since my e-brake also doesn’t work. Any way to bypass that while trying this out. I literally drive less than 2 minutes to work everyday, parked on flat ground in gear, so fixing the e-brake has definitely been on the back burner for a while. Apparently I gotta take out my bench seats to access the parking brake assembly that comes into the cab, and that’s gonna take a whole lot of time I do not have currently.

 

So it locks up in 4Hi?
That makes me want to think is in the front differential.
But I’m the type that likes to verify first, before throwing parts at it.

It’s late. My mind is slow tonight.
There may be a better way to test it.

let some other guys chime in.
In the mean time, I’ll think it over and see if there is a “better” way to test it.

 

I engage 4Hi, it blinks like normal, light goes steady on, then when I try to move, I get the smallest amount of movement in forward but I have to slip the clutch out while giving it a lot of gas to get any movement. When I try to go in reverse, I get absolutely no movement. Then when I disengage 4wd, it blinks like crazy and doesn’t do anything. I have to turn off the truck, roll it in reverse for a bit, then the 4wd fully disengages.

But thanks for the help man, will definitely try it at work this weekend.

 

Im stuck on what to do next here....(back story) I was hitting the trail in my 09 automatic sport taco and when I attempted to go from 2wd to 4Hi it did not engage and the 4WD/4Lo light started blinking continuously. When I got home I pulled the TC actuator off and came to find out the outer ring was pretty corroded. I cleaned it up the best I could and reassembled it. The blinking light went away at first, but when I cycled through 4hi and 4lo the lights came back on and still no engagement. Decided to replace the TC actuator. When I drove around the block to test it out the 4wd/4lo lights were gone. However, when I tried to engage 4hi the green 4wd drive light came on blinking and no engagement. When I went to check 4lo, the 4wd drive light came on solid and the 4lo light was blinking with a beeping noise and of course no engagement. At this point I decided to now check the ADD actuator. To my surprise the inside was in excellent condition and I even tested the little motor out which worked flawlessly. I am totally stumped! Can someone please point me in the right direction here? Thanks in advance!

 

It's possible you didn't get the actuator timed correctly, it takes several tries sometimes.
If your comfortable backprobing the terminals at the 4wd ECU, checking the voltages, and posting the results that would give us direction to where the problem is.

 

Ill give the backprobing a shot tomorrow and let you know what I find. Thanks!

 

So here are my results of the backprobing. The DL2 position wouldn’t give me a clear reading. It was just making the volt meter flicker basically.
The TL2 position would initially have 0v but when I reversed my steps back down to the 2H it would read 7.0v. Hopefully this paints a better picture of what’s wrong here!