Failing 4WD switch?

So I've been noticing an intermittent issue lately and not sure what could be causing it.

Occasionally when I change drivetrain modes, the 4WD ecu will essentially ignore the switch. I.e. move switch from 4lo to 4hi, and 4lo stays engaged. No flashing, no beeps, just ignores it and stays in 4lo. Move switch back to 4lo, then back to 4hi again, and it shifts normally. I've never had a single episode persist after one re-try, but it's done this two or three times now.

I think it's done the same thing going from 2hi to 4hi, but I'm not sure.

I do have the plug-and-play 2lo module from @Up2NoGood installed, but it's been there for almost 2 years now and this is a new issue in the past few weeks. The module works flawlessly otherwise, so I doubt that'd be the culprit

What do the wiring gurus think? Switch going bad maybe? or something deeper? As of right now it's a minor annoyance but I really don't want to end up stuck in 4lo one day, or in 2wd when I need 4wd.

 

@Dm93 can link you to his thread to check the switch voltages.

 

The only thing I have found is to use it, yes even in the summer. That is my pet pave I hate the dang thing I want my locking hubs and the lever back! It never has worked right for me day one.

 

https://www.tacomaworld.com/threads/4wd-system-operation-help-thread.742420/
I don’t recall if the actual switch test is included in that link.
It probably is, but if not…..

 

Yes, control switch voltages are in the chart.
I think the first thing to do is unhook the 2lo module just to rule it out.

 

Sounds like a good plan.
I don’t have one of those, but I know a guy that does

 

Oh I do exercise it frequently, it's not the actuators that are getting stuck, it's that they're not being told to shift for some reason

Thanks for the info! I'll break out the DMM and start poking at it.

I'll check the switch first and see if those readings are in spec or borderline. If they're kosher, then I'll try removing the module. Just because it's an intermittent problem and there's no way to know immediately if removing the module solves it.


Thanks for the input everyone, I'll start looking into it.

 

Oh it's being told to do some thing or it wouldn't sit there blinking. I push snow in low range usually it will shift into high but that too is a guessing game, low range is another story same issue getting it to shift out of low. Part of this maybe the manual trans I wonder if other manually owners have experienced this? This has done this from day one. Too me this is not an improvement all of the older Tacoma's I have had worked flawlessly with a shift lever. In Toyota's infinite wisdom decided it would be a good ideal to spin the axles full time on the electric shift any way. in days of the old ones I just locked the hubs when the weather was not nice and got pretty good just shifting into locked while driving. If it ain't broke don't fix it.

 

That's the thing, it's not blinking, beeping or anything. I'll go to shift out of low range, and it'll just sit there like I didn't even turn the knob at all, like the computer just ignores it. Then I put the knob BACK in 4lo to try again, and then click it back to 4hi, and it finally registers and shifts normally. I'm thinking theres a bad connection somewhere in the knob, or maybe in the 2lo mod.

I agree though, I may eventually do a triple-stick 4runner conversion on mine. I miss mechanical levers instead of switches and actuators.

 

Are you using the external switch for the 2low module or controlling it with the 4wd switch?

 

Controlling it through the stock 4wd switch

 

Ah, maybe the module gets confused at times if you move the switch too quick? Just a thought, I had mine that way when I first got it and it seemed to work fine but I didn't like that it would go into 4wd if I turned the truck off and restarted it so I installed a separate switch.

 

Yep normal. Mine will do the same thing. No rime or reason some times it just works.

 

Hmm maybe that's a possibility, but I'm not sure how, since the "trigger" for the module is holding it halfway in the dead spot between 2H and 4H for a few secs. Which i assume the module senses it's getting "NO" signal as opposed to "A" signal from the switch. Going from 4L to 4H wouldn't even factor that dead spot in. And I don't hear any relays clicking until I retry.

To clarify, when I say no flashing, I mean the 4WD and 4LO dash lights stay on as normal being that I'm in 4L. So it's indicating correctly, just not reacting to switch changes temporarily

 

Yes some times if you turn the truck off and back on it works or it just sits there laughing at you. I kind of need the damn thing to work my drive way is over a 1/4 of a mile and the last snow storm dropped just about a foot of new snow. Can't tell you how many times I sat in the drive way waiting for the 4WD to make up it's mind if it will work or not. Love my truck but the electric shift sucks.

 

I was referring to how the 2low module works, my 4wd works flawlessly but you almost always have to be moving slightly before it's gona engage 4x4. Once it's in 4wd it goes right into low.

 

Lucky you. Wonder if another manual trans owner will chime in.

 

The automatic will have a light load against the drive train where as stick doesn't.

 

Following, as I’ve got a mt with the 2lo module.
Once a month I’ll run my 4l wether I need it or not, but today decided to try 2lo just to see. Anyways, things aren’t smooth like usual. Going into 2lo (2h>4h, 4h>pause halfway then 2lo) it’ll either beep like it didn’t connect or connect but won’t come back to 4h (4h light is on) just stuck in 2wd.
Go back to 2wd, 4h still lit, then finally go out.
Try 4h again then it works.
I’ll try disconnecting the 2lo module soon and reconnect see what happens. Hoping it’ll fix itself after using it a couple times.
¯\_(ツ)_/¯