Trouble locking the diff and 4lo

I have a 2008 manual Tacoma with the 4.0L V6 and it has a passenger air bag on and off. For some reason, the diff doesnt want to lock and neither does 4low. I have to shut the truck off then when I turn it back on itll drop into 4lo. Then repeat the process to go back to 4hi. Any ideas as to what's wrong?

 

Honestly sounds like a communication error. It happens when you shut down and the computers re think of where they're at.

 

Any way to fix that? Didnt use to be that way

 

I have a similar problem on my 08 auto , when I want 4wd lo I have to shut off ing then restart, similar getting out of 4 Lo??? Bob

 

Glad I'm not the only one having this issue then, hopefully someone knows something

 

You can do a global reset. Disconnect the neg and pos battery cables and hold them together for a minute. Hook them back up. Test it.

That resets all of the modules.

 

I guess that's worth a shot... hopefully it's a more permanent fix because I'd only do that once. Sounds a bit extreme

 

Its not going to hurt anything. We do it at work when a customer says for example, their powers seats and power mirrors went out at the same time.

They are on the same circuit. We do a global reset and poof! Everything works again. Just giving out a simple, free idea.

 

Its the same thing as changing your battery out. Your just giving your modules time to re think things.

 

I'll definitely do that then, just want some that more permanent cause It is really annoying when the truck doesnt lock up the way I want

 

Totally agree! Maybe a toyo dealer can hook up a scan tool and see if they are any codes stored in the transmission control module. But that costs money!!

 

I have an OBDII and no codes are being thrown... the diff isnt locking making me believe that maybe something is up with the clutch depression

 

Do a search there are many posts on all the sensors and switches to get 4wd to function.
Just as a point you must be in 4 Lo to use the rear e-locker and get it to engage. There is a position sensor in the activator switch on the rear diff that receives a signal from the xfer case that its in 4 Lo. If 4 Hi comes right on the front diff coupler and switch are functioning. All 3 of these can have corrosion issues thru engagement issues. Believe the signals all go thru the ECU. Again lots of pics and info available.

 

Ok thanks for the info, I was wondering if the diff could be locked in 4hi, bummer it cant be. I'm going to check the clutch and make sure it is depressing all the way for 4lo, now all I have to do is figure out why 4hi isnt properly disconnected

 

OP are you stopped when trying to go from 4hi to 2hi? If so thats your problem... get rolling, switch to 2hi and let off the gas (and in your case push the clutch in) to unbind the driveline and ill bet it pops right out of 4hi (really helps if you are in a slight arch of a turn too)

To get into 4lo you must be all the way into 4hi (no flashing lights on the dash), be under 3 mph, push that mufuggin clutch through the floor, and then switch to 4lo. Reverse the process to get out of it.

Like stated stock you can only use the locker in 4lo... but there are a few simple mods that will allow you to use it whenever.

 

Yeah I've tried moving slowly to get the truck out of 4hi and it just flashes, I'm going to mess with it when I get home from work and try mashing the clutch down for 4hi. Does the passenger airbag have to be off as well?

 

ADD actuator maybe? I had the same problem and it’d just beep beep beeeep but never engage. Replaced the ADD actuator and all was groovy.

 

No passenger airbag should have nothing to do with 4wd functions.