881stGenRunner

I figured out what the problem was and the answer is in a few posts below. There is still good troubleshooting methods in the first posts

Let me preface this by saying I was able to apply power to the actuator on the back of the transfercase, get it in 2wd, and the lights are no longer flashing.

However, every time I try to engage the 4wd system it will not put itself back into 2wd and turn off the lights. In fact, it doesnt even make it all the way into 4wd. The 4 Green wheel lights and 1 Orange CDL light do not stop blinking.

I have been using this YT thread as a reference:

4WD won't disengage on 99 4Runner LTD - YotaTech Forums

I started by replacing the forward most switch on the Transfercase Actuator (Toyota P/N: 84222-12010), it seemed to be the fix on a majority of 2001 4Runners and i was hoping that was the case for mine as well.





I went to advance to check the codes and it revealed a C1224 - NE Signal Circuit. I have recalibrated the VSC system using this link:

https://mike-thomson.com/blog/?p=1143

I also purchased a new ABS/VSC/TRAC computer module. The FSM references this as the Skid Control Module (Toyota P/N: 89540-35370). This did not fix my issue either.

So to get it back into 2WD I applied power to the Transfercase Actuator plug. The 2001/2002 plug is 6x1 instead of a 2x3. See diagram below to see how I accomplished this.



Why is the truck not allowing itself to engage into 4wd or go back into 2wd? It's like there is something not sending the correct signal and it is putting the 4wd system into limp mode.

I am currently trying to sell the vehicle and I can't afford to let it continue to nickel and dime me at this point. If anyone has any recommendations, ideas, help, etc it would be very appreciated!

Thank you,

Brandon

FogRunner

Had the same problem with my 2001 4Runner and kept swapping sensors on the transfer case with no luck. Finally swapped out front ADD actuator and problem solved. Don't buy the Dorman brand, get the OEM actuator.


Fog

881stGenRunner

Fog,

Interesting. I was able to put power to the front diff actuator and get it to move. I will try again and see if there are any unusual sounds coming from it. Hopefully I can find another one cheap if that is the case. I have already sunk about $435 dollars into this

FogRunner

The problem isn't the actuator motor it's the position sensor inside. When they changed from the vacuum to the electric ADD actuator they moved the sensor to inside of the housing.

881stGenRunner

Okay so we just tested the front differential actuator again and this time there was no movement. We performed the following tests (3 & 4):



Test 3(b) showed 3.0 ohms - Check was good
Test 3(c) yielded no results. There was no resistance between either of the terminals and the body/ground.

Test 4 with Terminal 2 as (+) and Terminal 6 as (-) only made a grounding noise from the actuator.
Test 4 with Terminal 2 as (-) and Terminal 6 as (+) did nothing at all.

At this point I am leaning towards a bad front differential actuator. I removed the new Toyota switch and I am going to attempt to return it to Toyota tomorrow.

Keep the suggestions coming!!

Thrashpipe

You ever get this fixed? I have the same problem,
I've been researching and poking around underneath trying to figure out why my 4wd is acting up. I have a 2001 4runner sr5 auto with multi mode 4wd.
When I try to engage or dis engage (depending on which it's stuck in) I will sometimes get a noise like a motor working the acuator, most times not) but no matter what the dash indicator flashes non stop, sometimes when it's trying to do something the light will flicker really fast. I can get it in and out but it takes a lot of work and the dash light remains flashing no matter what. I have replaced one of the position switches on the transfer case actuator to no avail. Any ideas?
~Aaron

881stGenRunner

I did.

It ended up being the switch inside the Front Differential Actuator. I simply ordered a new one from ebay - use this search and find one there (http://www.ebay.com/sch/i.html?&_fro...tor%20Assembly)

I loosened up the Front Differential Mount Bolts then let it sag, unbolted the actuator from the diff. You're going to have to be patient and find just the right way for it to come out, it will though. Clean the mounting surfaces, put some black RTV on the surfaces and bolt the new one it. Easy fix - shouldn't take more than 1-2 hours.

881stGenRunner

You can "benchcheck" the old and new front actuator by pulling the slack in the harness down a little bit and plugging an actuator in.

Turn the truck to the "on" position, no need to actually start it.

Push the AWD button and see if the fork moves left to right

Thrashpipe

Thankyou, I hope it's the issue, it will move sometimes and other times do nothing and other times twitch around like it doesn't know what to do like a bad signal. It worked perfect when I first got the truck but after a day of drowning the underside time after time for a day out mudding , it now is messed up lol I thought these were made to last but to be fair it is older.
while I'm thinking of it, what are the pins to test movement for the front one I'll do that while it's still on. Also if the test works both ways is it then a switch? Or relay or something? I'm sorry, transmissions and diffs aren't my area. I can rebuild an engine all day long and various other things but trannys and gears and positions all confuse the crap out a me. >.<

TheDurk

Recognize that your 2001 4Runner (along with the 2002) has an electric front actuator and the troubleshooting and repair of those is totally different from the vacuum system discussed in this thread and on 4Runners prior to 2001.

Use the 2002 manual here:

http://tacoma.site40.net/4Runner_96-...acsy1/insp.pdf

Thrashpipe

I realize that, that's why I'm posting here because "1stgenrunner" was posting about the same truck I have and it's been hard for me (very new to this forum thing) to find someone who has worked on this very issue reguarding the electrical actuators.
I'm confused now because this is not a discussion about vacuum driven actuators. But Thank You for the link, I will study it.

881stGenRunner

What do you mean by the sentence I highlighted? How do you make the actuator move with 12v power? If so, look at the post I had with the FSM page. Start with steps 3(a), 3(b), and 3(c). That is the testing procedure for the front diff actuator. Mine failed on 3(c) - if yours fails 3(c), I would say it is toast.

Thrashpipe

I apologize, I thought the picture of the pin out was for the transfer case actuator. That's why I asked what the procedure for the front diff actuator was. Sorry guys, I'll work on testing today after work and see what I come up with.
thanks "the Durk" I was able to find the entire Haynes pdf , should come in very handy. U guys rock!

881stGenRunner

Its all good dude. I realized last night it was a little tricky.

Let me know if there is anything else I can do to help you figure this out

Thrashpipe

One other question, the link I was sent included testing the ADD relay. But never mentioned where that's at, any idea? Do we have one? I've tried looking it up but can't find anything saying (this is where it is for sure) thanks again!

TheDurk

Was that my link? I wouldn't think so. 5-speeds have an ADD relay, and it's in the passenger kick panel. But that was from the 2002 manual and there were no-5 speeds in 2002. Autos have a 4wd ECU and that is in the driver's kick panel. (Not totally sure if I remembered the sides correctly.)

If you want the rest of the 2002 FSM and EWD, here is the link:

http://tacoma.site40.net/4Runner_96-...g/contents.htm

2002 and 2001 4Runners are perfect clones, as far as I have seen. 2002 was the last year, so they were done making changes.

Thrashpipe

Okay, so i did the tests;
first testing resistance between 2-6 (nothing)
Then 2 or 6 and body ground (nothing).
Then I applied voltage between 2 And 6,
first 2 - 6 + ( motor moved the sleeve)
Checked continuity (good, no signal)
Then 2+ 6- (motor moved the sleeve)
Checked continuity (good, signal)
I then tried a couple more times and it moved back out and then back in, however when I wanted to disengage it one last time, nothing. Now it won't move either way and I get the "engauged " signal from 3-4 And she won't budge. Over heat? Should I try again in a bit? Still no responce from the switch in the cab. ( I should mention I checked continuity from that as well and it was fine as expected and is receiving voltage fine). 10v with the truck off.

Thrashpipe

Sorry I didn't see your post, yes it shows checking the relay.

Thrashpipe

Update, now that it's litterally stuck engauged the cluster shows the 4 green tires but only sometimes, if I turn off the key and turn it back on it will flash some times and other times it stays green.

Dave E

Thrashpipe did you ever resolve your problem?