4lo light is blinking

I'm having the same problem, just found the following over at the other forum. WIll be looking into this, might just need (if the ground strap is there) remove the strap and clean the grounding spots.
https://www.toyotanation.com/threads/ground-strap-replacement-and-4x4.1779960/

 

Is your shifter sticky at all? Weird question, but I would put my truck in drive, then this would happen and I’d realize my drive wasn’t lit up. I had to hard shift it a few times from
Neutral to drive to get drive to light up and then it was told to go. It was my neutral safety switch. Hit it with some kroil and it’s back to functioning fine.

 

Well I'm back. Still the same problem if your keeping up with everything I have done then you know what is going on.

NEW UPDATE: Took my truck to the Toyota dealership who said their equipment would get into the bank of the vehicle and find out what the problem was.
They checked it and no codes? Funny same thing happened to 3 other people but they were the best! They said leave it so I did.
They drove it around the parking lot for 2 weeks. It never died on them so they were able to see what the vehicle was doing or recheck after.
Called me to come get it. I brought it home and drove it around several times on & off around the acreage. After 2 weeks last night the truck died on me again. I had to pull it to my house.
Today I loaded it up again and took it to another mechanic to see what they can do.
So has anyone else not had the same problems? Thought I would check in again to see.

 

2012 tundra, 5.7 4wd.
Looks like a common issue. Toyota can't figure a dang thing out. Had last time 27 days. Won't go into 4 ho or lo. My actuator motors look like new, both motors work in both direction(took assemblys out and tested with power. I readjusted the timing gears in each so they are at the neutral position and pulled the adjusting rods in the case to neutral. I can hear the 4hi motor function when turn switch but It never engages. I do hear the power control mod behind the glove box which sendsbtje signal to transfer case. Every now and then I get the 4lo on engine startup but goes away after turn truck off and back on. I have not tested the motor in the front diff which could also be an issue. It won't engage in xfer case if both actuator are not functioning. About to just order a transfer case and go from there.

 

If I were cursed with this issue I'd connect Techstream the moment that light comes on and look at each sensors output as something is triggering that light and from what everyone has said, its not in 4 low, so it's not like the actuators moved while the engine was off.

The answer will likely come from Techstream. That software can read things you won't see easily with a scanner.

 

Pics of driveshaft.

 

Holy mackerel, 2yrs with no 4wd and I got it working tonight. Got the 4hi actuator lined up right with the tab to actuate the front. I had made a post earlier with photos where I had switched the gears around and I ended up finding out the gears are different sizes so I deleted to not cause confusion. This caused an issue with the 4lo not to fit down right as there was too much tension from gear to actuator rod. I have not tried 4lo. Was too happy that 4hi works. Found out my newly replaced driver's side CV axle is grinding when turn. It's a cheap one so will get an OEM. Passenger side boot blew out so will do the same on that one. It was all about getting the hi gear in the right position. 2yrs and multiple attempts at aligning. Smh. Toyota couldn't figure out a darn thing with my truck. They definitely don't work on the motors, just replace the whole unit.