2016 TRD Pro Transfer Case Stuck In Low Range

Greetings from Australia,

I'm having a problem with my 2016 Toyota Tundra TRD Pro, which is an import from the U.S. (since Tundras aren't stocked here). I bought this truck because they are known for their reliability, upgrading from the Hilux. However, it's currently stuck in Low Range gearing.

Annoyingly, it is to be able to shift into 2WD, but it stays in Low Range (RPMs stay high), but I can't get it into 4WD High Range (4HI) or 2WD "High Range".

Here’s what I’ve done so far:

• Changed the transmission oil and transfer case oil to new oil, but it hasn't fixed the issue.
• Jacked up the truck so all four wheels are freely spinning freely and periodically moved the car into drive and reverse while tapping the transfer case with a hammer to see if it freed anything up, but that also didn't work.
• Had the car scanned with an OBD2 reader and will attach the result of the fault codes that are reading on the reader.
• Attempted to drive the truck and shift between 4WD modes
• Put the truck in reverse and switched between 4WD modes
• Neutral cruised down hill to see if it would do anything
• Put the truck in 4LO and hard locked steering both ways, and then attempted to go to 4HI, then 2WD (still stays in Low range)

Additionally, I've read a similar forum post where someone else had a similar problem with their Tundra being stuck in low range due to the transfer case shift actuator being in an incorrect position.

When I took my shift actuator apart, my gear inside the transfer case was also in the same position, I followed the instructions in this post and now the actuator is moving the gear to the correct 4LO, 4HI & 2WD positions, but remains in Low Range gearing.

Here are some additional details that might help:

1. The issue first occurred when I was reversing the car in a grass whilst raining. I didn't follow the correct procedure by putting it into neutral before switching it into 4LO. I put it in reverse, switched the dial to 4LO, and started reversing (nice learning experience)
   
   
2. I haven't done any extensive four-wheel driving or any related four-wheel driving recently.
   
   
3. I have periodically used 4WD in this vehicle before (although it has been done incorrectly).
   
   
4. There is no unusual noise coming from the vehicle apart from a high pitch whine when driving, which I assume is usual when in low range.
   
   
5. I've tried switching the 4WD modes while both stationary and moving.
   
   
6. There are no other warning lights on the dash besides the flashing 4HI light.
   
   
7. When switching to 4LO the truck then flashes the 4LO light and has a solid 4HI light
   
   
8. I have checked the polarity of every fuse to ensure no blown fuses
   
   
9. Battery voltage is normal, and connections are good.
   
   
10. No recent repairs or modifications.
    
    
11. No signs of physical damage to the wiring or connectors around the transfer case or underneath the truck.
    
    
12. Multiple attempts at disconnecting the battery for a few minutes, hours, days, to reset the system, but it didn't help.
    
    
13. Attempted to switch it back to 2WD when it was raining again on the grass (I'll admit this one was a hail mary)
    
    
14. The only way I can make the dash correctly display that it is in 4WD Low Range is by moving the dial selector to 4 LO, disconnecting the battery, reconnecting the battery, and then starting. This is the only way to make it show the solid orange 4 LO and the green 4 HI lights on the dash with no beeping or flashing.
    
    
15. When then attempting to go from 4LO to 4HI (correctly by shifting into neutral first), and shifting to drive and driving down the road (or on stands, tried both), the 4HI light will flash on the dash.
    
    
16. When then stopping, and changing the selector from 4HI to 2WD, it will shift to 2WD, but the 4HI light will remain flashing on the dash (no beeps), but the gearing will remain in Low Range (RPMS high).

I am hesitant to take it to a Toyota dealership because I believe they will shrug and not know anything about Tundras and change me a stupid amount of money for them to piss against the wind, or they will google it and find this thread. (future hello to Toyota Australia..)

It would be ideal to go to a car wrecker and slap a wrecked transfer case on it, but as the Tundra is an import here, there are none available, buying an eBay case is an option but for $2,xxx Kangaroo dollars + potentially getting scammed (not entirely sure how USA eBay wreckers are for their reputation, but as for Aussie eBay wreckers, flip a coin on if you're getting a good part) for something that could be an electrical issue would make me shed Koala tears if I continued to have the same issue.

My next steps at this stage from all I have tried is to take the transfer case apart and see what is going on inside, but I thought I would make a post here first to see if anyone had any other suggestions (bigger hammer?)

Additionally if anyone can vouch of a US based wrecker, I will happily liaise with them to organize shipping.

Any advice or suggestions on what else I could check or try would be greatly appreciated!

Thanks in advance for your help!

 

I'm going to reserve the first post on the thread for when I eventually find the solution to the problem I will update this post to save crawling through the entire thread.