Another 4runner won't come out of 4wd thread
 

My wife has a 2001 4runner sport that won't come out of 4wd after pressing the button. I have searched a have not been able to resolve this problem. I have replaced the switch on top of the transfer case and that seemed to help for a while.

The other day she accidentally hit the button and I had to get under the 4runner again and remove the actuator and manually switch it back to 2wd. Well I finally decided to look into the electronics of this thing and got a wiring diagram and a pin out chart.

To make a long story short, when I ground the #19 wire (black/lt-blue) wire with a Power Probe on the 4wd computer, I can hear actuators move and the transfer case goes into AWD with no blinking light. I can then hit the 4wd button and it will go into 4x4 with no blinking light. If I shut the engine off and restart I get the blinking light again. I can also hit the AWD button to off and ground the #19 wire and it will bring it out of AWD. No blinking light and all is good, in 2wd.

This #19 wire goes to the engine ECM, the VSC, the 4wd computer, the ADD computer and the + side of the ADD actuator. There are no locator switches in this circut. When Awd button is pressed this wire has power to it.

I assume I have a grounding problem some where and am hoping that some one here has run into this issue so as to make my life a lot easier. Maybe I have missed some thing in my search and if so, my bad. Any info or advice is much appreciated.

Thanks

My truck has been stuck in 4WD 2 or 3 times over the years. I found jacking it up and getting all four wheels off the ground (truck on stands) allowed it to release - as if something was binding.



Andreas