4WD issues

My 4 wheel drive light flashes randomly when I drive now. When I start my truck on 2wd I can hear the clicking 4x4 trying to engage. The times I try to engage my 4H it doesn't engage. I have tried to get it set on all the gears. The mechanics at toyota are trying to say that I have to be moving in drive or reverse for it to engage. anyone else have this problem.

 

It helps to be moving,slowly. Manual stated you can shift into 4HI up to 60mph, but personally I wound say not more than 10mph

You need to drive a few miles in each one at least once a month to keep everything oiled and moving.

 

Have you been driving your truck in 4HI every month for 10 miles?

 

You dont HAVE to be moving. Atleast not in my experience, although it is easier for the truck to do so while moving. The manual doesn’t state you have to be moving

 

thanks. No I havent driven it in 4H for like 2 months but I've been driving in 4LO for the past 2 months every time I go to the desert

 

no I haven't used it since I've started going to the desert more often. been using more 4LO

 

I've always had no problem when I had it in neutral to engage. all of a sudden it stopped engaging about 2 weeks ago

 

I switch into 4h going 40-45 mph a all the time on straight stretches of road to keep it oiled never had a problem.

 

A truck that new, shouldn’t be an issue even if haven’t been using it every month. Time for the dealer, I think.

 

totally safe to engage at speed as per the manual. the ECU won't let you beyond 60 (or 58 or something?), but up to that speed just be gentle on the throttle and it's smooth as silk.

 

I was telling them so is it normal when I start my truck and the 4wd tries to engage when it's in 2wd. they're saying that nothing is happened since I've taken it to the dealership.

 

I'm thinking you 4 wheel drive control switch is bad, even though you have the selector in 2wd, a part of the switch might be trying to switch it. just my opinion, try to disconnect it or pull the fuse?

 

No, it is not normal for your 4WD to attempt to engage during startup if your selector is set to 2H. If they are telling you different at the dealership, take it to another dealership. If you are stuck with no other nearby dealerships, call Toyota Corporate and start a case before you return to the dealership. They will advocate somewhat on your behalf. Further, with such a bad start of a relationship with this dealer, get everything in writing and keep all service papers/ documentation - you never know when you will have to refer or use it to defend your case or to insure your warranty coverage.

 

4 high you can be moving.... 4 low MUST stopped and in neutral.

 

As NoOne said. Truck will check the feedback position sensors on startup and at each detected mode change request (2hi switch to 4hi, etc). If position sensor on the actuators show the actuator isnt in desired position on startup or at mode change request, you will hear the relays click, commanding actuator movement.

If you were in 2hi when you shut down, and selector was in 2hi on startup, and you hear the actuator relays clicking, there is almost certainly a problem in the actuator or the actuator wiring. (Could be add or transfer case, cant tell.) Chances are (in my opinion) it's the add or transfer case position sensors

Generally shouldn't be too hard to diagnose with techstream, or some ohmmeter work....

 

Pretty sure you can go up to 3 MPH and go into 4 lo

 

I’ve always come to a complete stop, neutral, shift to 4lo.

In my old Taco, shifting to 4lo while moving = gear crunch.

 

On;y thing I have noticed, if your stopped with your foot still on the brake in "D", it usually won't go into 4x4. Moving slightly seems to be no issue but not always an option. 4Lo is another mater, that can be quite finicky at times and at others times, no problem.

 

I had this issue and it was the front diff 4wd actuator. It has a metal contact that isnt soldered and in time with offroading it can get less continuity resulting in 4wd failures, you still hear the click from the transfer case but you get failures. Toyota would not work on my truck because of aftermarket lockers. Luckily It was an easy fix, just soldered the connector instead of the regular contact that toyota thought would work.

 

Here is a thread on them
https://www.tacomaworld.com/threads/how-to-trouble-shoot-4x4-actuator.263525/