Mystery button on my 2001 Limited 4Runner dash

I don't have my user manual, not really sure if I ever had one, bought this 2001 back in ~2010...

But I never thought much of this button before, and I've taken my 4Runner off-road in 4WD plenty of times, mostly at the beach, but it works great. Just a pushbutton engagement on the 4H-4L shifter to put it into 4WD.

Initially I thought maybe it engages a rear diff locker, but checking under the vehicle, there is no locker hardware on the rear diff.

Anyone with a Limited recognize this button and know what it does? The symbology on it made me think it had something to do with 4WD, but maybe it's for disabling traction control? Not sure, could use some help!

Thanks in advance!

 

It's for center diff lock.

 

It's on all 4x4 4Runners for 2001-2002. I have it on my SR5.

 

Yep, you have a lockable center limited slip differential you can use in any conditions including on-road.

Just not when locked.

 

Thanks, I feel a little embarrassed I didn't know my 4Runner had that "feature". Not sure how that'll help me off-roading other than I'll need to make sure it's "locked" from now on, would rather have the locking rear diff, like my 2022 Taco features.

 

It really is a great four-wheel drive system, it's funny how it's more advanced than the one they offer now.

If I recall correctly, they discontinued the rear locker availability in 2000, 2001+ got ATRAC instead.

 

I'm guessing that the ATRAC must have been viewed as better all-around solution to improving traction, both on-road and off-road, but when I was into hot-rods (still have a 98 Trans Am), I always viewed any kind of brake upgrades as things that slow me down, not make me go faster! And so that's the feel I get with ATRAC as well, the computer wants to apply brakes to spinning wheels to improve traction for the non-spinning wheels, whereas the locker is just brute force GO power.

The locker rear ends are still sought after very highly, kinda like the superchargers and hood scoops are still.

 

I agree. There are some people that will tell you that ATRAC is better than dual lockers, but I disagree for the same reason that you stated. Anything that works by engaging the brakes is going to slow your forward progress.
That's cool you still have your T/A, I have a 2000 Formula.

 

ATRAC's main merit is being cheaper to produce once the brakes got ABS and are fully computerized such that they can be independently actuated. Mechanical limited slips and lockers cost extra. ATRAC just required a circuit to control brake pressure on each wheel. The engine output is already moderated by the ECU.