4x4 only engages when truck turned off...

Morning,

So to make a long story short, I work and live in two different, no where near one another locations. I leave my truck at my sisters so she can use it while I am away, so it does not just rot in my driveway.

My truck seems to have an issue that I cant think of the problem to. The 4x4 only engages if you stop, shut the truck off, flip the switch, then start the truck back up. If you flip the 4H switch while rolling down a road, or even stopped, it will not engage. The light does not even light up, and no sounds can be heard.

Anyone have any ideas?

Truck is an 06 doubble cab automatic if that helps.

 

When the truck is on. Stop it. Put it in neutral. Flip the switch and it should go into 4x4.

 

You shouldn't need to put it into neutral to go into 4Hi. The light should come on and blink a couple of times before engaging. In my experience (manual trans) it helps to take your foot off the accelerator and/or press the clutch in if it's taking a really long time.

 

Ya I regularly switch into 4-hi at any speed up to 60 mph and have had 0 issues with this. I definitely take the load off before switching it though.

It sounds like another issue though. If 4-HI is waiting to engage the light flashes while it waits for things to be lined up. If the light isn't even flashing, then you have a real issue. Take it to the dealer if still under warranty.

 

It is an automatic, so no clutch needed. BUT they (siser and brother in law) have tried everything. Putting it in neutral, coasting, stopping and using park, park break on and off, even slowly backing up like the good ol days. The 4x4 light does not blink to indicate that its trying to switch into 4H. As for being under warrenty, its a 2006 so long out of any warranty

 

heres the vid my brother in law sent me, hope it loads

 

Try again there tex

 

Sounds like the actuator at the front differential is having a tough time grabbing the 4 wheel locked position .When you select 4X4 , the transfers case shift hub moves from 2 wheel to the 4 wheel drive position . When the transfer case is in 4 wheel drive ,the switch on the transfer case sends 12 volts to the front actuator . The actuator then moves the front axle shift fork from 2 wheel drive to 4x4 . The light will only come on once the shift fork has moved to the 4 wheel drive position .
How to diagnose ?
Select 4 wheel drive with the front actuator removed and make sure the actuator moves to the 4x4 position .

 

It is weird that the light isn't even flashing though. Like I've been parked before then switched to 4x4 and it couldn't go just because things weren't aligned. I moved a bit and it went. But the whole time, the 4x4 diagram light thing was flashing saying it was trying. I think this might be more an ECU problem or something.

The light only goes SOLID when 4x4 is engaged, but it should flash the whole time is is trying to engage.

 

True, I just find it odd the indicator isn't even coming on but it works fine every time if you switch it before you start the truck. Doesn't sound like an actuator.

 

Well. My current thought is the switch itself might be warn out. Br
other in law with be voltage testing it tomorrow.

Thanks for the ideas rhk everyone. Its hard to diagnose the problem when I
myself are so far away from it. I fly home on the 2nd so I'll be able to go from there.

If it were possible though, I'd buy you all a round for the help!

 

Hah, off topic, but how much would you say you invested in that setup? I'd love to do it someday...

 

Not bad at all. I figured it would be double that. Ideas... You have any links to write ups?

 

Awesome, thanks for the info. You've got rep. Sorry OP for the threadjack, the electric 4x4 stuff sucks in these trucks.

 

No worries. Really considering the manual swapyself now. Hate electric shift.

 

Oh these trucks still have plenty of stupid electronics!

 

Well, if I can eliminate any more of the electronics, I shalt! So I think after I re gear my diffs, that manual T case will be next on my list. Speaking of electronics, turns out the switch is on its way out. Brother in law took it apart, cleaned it, used some dielectric grease, and now 4x4 works like a champ!

 

I'm having the exact problem with my 05 Tacoma 4.0L, 6 speed standard trans, TRD O.R.

It consistently goes into 4WD if I turn the switch to 4 while she's off, then turn her on. She'll go into 4 every time that way. And switch between 4 hi and 4 low with no problems. Rear diff lock also works fine. But she will not go into 4wd when already on.

I just tried a brand new switch. Nothing. My next step will be the computer behind the glove box, which costs $260!

I know this thread is months old, but every thread I've read like this gets derailed into talking about the manual conversion. I want to know what the end diagnosis was!

Thanks.

 

Problem went away on its on for a while. Now its doing it again. Frustrating as hell. Only new symptom is I can hear the relay kick in from behind the glove box. Its one hell of a headache. I knoe its not the actuator because if It's in 4x4, I can flick it from hi, to low, and off amd listen to tthe actuator work like a charm... unless it fully disengages to 2x4... then I have to leave it in 4 hi and re key the ignition to get it in 4 wheel again.

 

it's the automatic transmission ECU doing something I betcha

I had a similar issue in a 4runner, one of the brakes in my auto tranny didn't
work when neutral going for 4lo...shut it off, start back up, always worked.

turned out it was the tranny ECU not doing it's job correctly