4WD actuator problems - feedback?

Recently had 4.88's and an ARB rear locker installed. Shop made a mistake during setup of the front diff: forgot a piece of copper tube in there which they used as some sort of "alignment trick" while setting things up. Truck wouldn't shift into 4HI, made all sorts of nasty noises from the front, got stuck in the "flashing 4x4" light stage for a few days. They say the copper piece (being soft) got shredded and didn't actually harm anything, but they cleaned it all out, replaced a few parts (can't recall what they listed off over the phone last night) just to be safe, put it all together with fresh oil.

But the truck still won't shift into 4HI.

Problem seems to be with the actuator as it didn't want to work. So they replaced it with a new one, and tested the new one prior to installation (it worked), but it also doesn't work in the truck.

They had two thoughts:
1. Something got messed up with the new actuator while they tested it off the truck.
2. Electronic codes thrown by the initial problem are preventing the actuator from engaging, and codes need to be cleared at Toyota.

#2 seems more likely to me. However, they've also ordered a new genuine Toyota actuator as one more replacement (guessing the one they used the first time wasn't OEM), but don't know how long it'll take to get that one in.

Is there a third possible scenario/problem to look at?

 

I cant imagine a code preventing the truck from shifting into 4wd.

It seems more likely that you have a transfer case issue caused by the front dif, likely torqueing a driveshaft causing something to be misaligned and thus wont engage.

 

I think at this point I would tell the installer I am taking the truck to a Toyota dealer and they need to cover the bill.

 

I did think that I heard/felt a few light bangs coming from the transfer case during this whole process. They were spread out over some ~10 minutes of driving (back to the shop). I'll pass this throught on to the techs.

 

The shop offered that as a possibility, and it's one I'll consider a bit later. Despite this mistake, this guy came incredibly highly recommended by both independent people and local shops, and even the ARB tech knew him by name and said he's "one of the best."

He's willing to fix the problem and make it right - I'll give him the chance to do so for now.

 

mines stock but some times wont shift in out of 4wd, have to goto neutral changed to 2wd/4wd and the light will just keep flashing and ill have to reverse a couple of feet, drive a couple of feet until it engages

 

While working on 2wheel low mod for the third gen, I caused a lot of error codes during reverse engineering. I had all kinds of electrical wiring shenanigans that I attempted.
In general, these codes are stored in the ECU even after you fix a problem (without any remaining dash indication), until they are cleared with techstream.

In terms of locking out the system, I found power cycling the truck (ignition off to ignition on) always cleared any faults and restored system functionality if I fixed the underlying cause.

However I may have learned something that is causing you an issue. The front actuator (ADD actuator) can be inadvertently driven into invalid positions. The truck checks the 4wd system on engine start, and during any command position changes. If the system detects any component that is not in a feasible position/operating mode, it blinks and locks out.

Specifically, the front ADD has a total of 3 limit switches and the motor. The system checks that the 3 limit switches correlate to an acceptable position. It doesn't have to be the correct position, but it does need to be valid. If for any reason the actuator gets driven slightly past the limit switches, such as while installing it, it will enter an invalid position. The ECU detects this invalid position and locks out the system. Power cycling the truck doesnt help, as the system checks at every start up.

If this is the cause, you need to manually (electrically) move the ADD to a valid position with the truck off (with ADD installed), and it will then recover when you power cycle.

If this is the cause, here is how I fix it.
Remove skid plate if applicable.
Jack up front wheels to allow ADD to easily engage/disengage.
Access the 6 pin connector on the ADD.
Locate pins 1 and 2 (these will be at 1 end of the connector, dont recall which) they correlate to larger red and light blue wires on the truck side of the harrness)
Jury Rig up some wires to connect to pins 1 and 2 on the ADD side.
Momentarily apply about 3-6 volts across pins 1 and 2. (I used 3 AA batteries from a flashlight battery pack). You should hear the actuator run. You may need to spin the front wheels to improve lock-in. If you dont hear the actuator cycle, reverse polarity.
Cycle the actuator several times back and forth, reversing polarity, to get a feel for it. It should take about 1 sec to travel.
Finally. Cycle the actuator 1 last time, leaving it in MID TRAVEL. The goal is to not have the actuator at either extreme, just somewhere in the middle. (At either extreme, the wiper positions are invalid, and actuator movement is locked out, as a fail safe.)
Plug ADD back in to truck, power cycle truck, and verify that truck is now happy.

I cant guarantee this will fix it, but I think there is a good chance.

(Edit, I discuss similar issues a little bit in 2whl lo mod... buried somewhere I this thread I think https://www.tacomaworld.com/threads/lock-stock-and-2wheel-low-3rd-gen-diy-mod.536677/)
Questions?

 

That's fantastic info. Thank you very much. Passing it on to the shop.

 

Good luck
Let us know how it goes.
If that doesnt fix it, will really need a copy of techstream and dongle to troubleshoot (without just poke and hope...)

 

I the shop a copy of your post and asked them to run through the procedure you outlined. They've already made an appointment with the local Toyota dealer to take the truck in tomorrow morning, but I'm hoping it can be resolved today. As always, timing of the problem is pretty bad, and the sooner I get the truck, the better.

 

3. Your installer messed something up. If it worked fine when it got there, it needed to work fine when you pick it up from there. If they need to take it to Toyota let them, not you.

 

No luck last nite I am assuming?

 

I don't know yet. The shop replied with a positive note re: your comments around 8pm, but I don't think they actually tried to do the steps you suggested. I think they want to Toyota to have a look first (this morning). I'll follow up this afternoon if I don't hear anything before then.

 

Heard some news: dealership confirmed that the ADD is the problem. Shop ordered a new one through Toyota, which will arrive tomorrow morning and be installed. Hopefully that takes care of everything.

As far as I know they haven't tried the "manual" procedure you outlined, @BigWhiteTRD. A bit of a shame, as I suspect that would get the problem resolved quicker and cheaper.

Fingers crossed for a pickup of the truck tomorrow afternoon.

 

its teh ADD
one of the guys I wheel with here had a similar issue with his 2nd gen and its the same for ours.

shitty ADD he had it fixed under warranty by dealer.

This shop fucked yours. So fuck them, let them pay for the repair.

Dont take a fixed something that broke by resetting it when you can get a replace broken part to fix lol.

 

As long as it gets fixed in a timely fashion, it's all good (in my opinion).

It took forever for the dealer to diagnose the issue for @NightForce27 when the forum was 100% sure after about 5 mins. https://www.tacomaworld.com/threads/fun-service-visit-should-i-be-concerned.547739/

 

In case anybody is interested, this table (from the service manual) shows what the ADD is supposed to show for each position. If the ADD is operated too far in either direction, the feedback wipers show open (per my recollection), leading you to think the ADD is bad. First time I did it, I thought I had hosed up the truck bad...

 

Heard back from the shop. They installed the new ADD, no dice. Still doesn't work. Says the actuator isn't getting voltage and is taking it back to Toyota. So frustrating.

 

Sounds like they need to try @BigWhiteTRDs method.

 

Shop says the front prop shaft spins, as do the tires. I believe that means the ADD is engaged, but the transfer case is not, which suggests that the problem is at the TC. Is that a reasonable assumption?

What's worse, I was just told (by a buddy who's a tech at Toyota) that the TC's actuator cannot be replaced without replacing the entire TC (Toyota doesn't sell the actuator alone). That's going to be a nightmare and a half. To make matters worse, in some 9 days I'm moving to a town 3.5hr drive away from where I am now...