4WD lights won’t stop blinking

[gtg339y]

I went and had my front and rear differential and transfer case oils serviced today. Afterwards I engaged 4 HI and drove with it on for a little while to make sure there were no issues Then I turned it back to 2WD. No issues. Later in the day I tried to engage 4 HI again but it never engaged. The lights just kept blinking and it even says VSC Off now too. I have tried the different tricks: accelerate, stop, reverse, neutral, etc.

Does anyone have any ideas?

 

[gtg339y]

Would love some help. Drove it around for about 50 miles today. Still stuck in 4 HI and lights are blinking

 

[4OYOTER]

Maybe try shifting into neutral and then 4hi, then back to 2wd.

Also try shifting into neutral, then 4hi, then 4lo. If 4lo will engage than hopefully you can stop. Go neutral again, then back to 4hi and finally 2wd. (Do this at your own discretion, I don’t want you to somehow get stuck in 4lo!)

If you have the 4x4 instruction card on your driver side visor, follow it to a T!

When was the last time you went in and out of 4low and locked the center diff? This is probably nothing to do with your new fluids and rather an actuator issue from lack of use.

 

[gtg339y]

Thanks man. Already tried all that. No luck. I was thinking actuator too but it worked just fine right after leaving the shop and getting fluids changed . It was about 6 hours later when I put it in 4 HI again and it got stuck. So it’s weird that the actuator would have worked and then not work 6 hours later.

Been driving all over the place in 4 HI. Hasn’t come unstuck yet...

 

[Doozi]

Are you sure that it is in 4HI? If you were in 2HI, tried to put it into 4HI, and it has been blinking since that's typically an indication that the 'operation' failed.

 

[4RunnerMexico]

Toyota Tech: Defeating the ADD System

This site is pretty good, Just move the fork in the front diff to the disengaged position and see if that changes anything

 

[Johnny4runner]

My guess it that it is your ADD actuator also. I have a v6 4th gen also and from time to time have issues. The ADD actuator is not easy to get to. When I had my front diff out I sprayed some WD40 into the actuator breather and have not had issues since.

Toyota Tech: Defeating the ADD System

This site is pretty good, Just move the fork in the front diff to the disengaged position and see if that changes anything

The 4th gen ADD is similar, but elctonically actuated. Not sure if you can defeat it in the same way without creating an warning light.

I’ve thought about replacing the stub shaft with a v8 stub shaft that does not have ADD. Would still have to fool the computer into thinking it was actuating. I think some of the SAS builds use a switch in the cabin to send the right signals.

Best, J4R

 

[AThomas0312]

I went and had my front and rear differential and transfer case oils serviced today. Afterwards I engaged 4 HI and drove with it on for a little while to make sure there were no issues Then I turned it back to 2WD. No issues. Later in the day I tried to engage 4 HI again but it never engaged. The lights just kept blinking and it even says VSC Off now too. I have tried the different tricks: accelerate, stop, reverse, neutral, etc.

Does anyone have any ideas?

If none of that works, check to see if you have a bad wheel speed sensor. I know its random, but those lights come on with a bad WSS

 

[gtg339y]

Thank you everyone. So after driving around for a few days it finally came out of 4HI and went back into 2WD. A couple days later I tired to go back into 4HI again to see if it would work properly. It got stuck again. I just dropped it off at the shop that did the services a little over a week ago.

I’ll see what they say is the diagnosis but will also have them try your recommendations as well.