4 low oops with automatic transmission

I accidently engaged 4 low while moving. I was shifting out of 4 high and turned the knob the wrong way. Barely moving when I made this mistake...less than 2mph. Darned electronic controls and knob anyhow. The light indicator when wild. 4 low appeared to be actually engaged. After trying all the usual stuff driving a couple of blocks (forward, reverse, turning engine off and on, turning front wheels, applying brake with trans in neutral, etc.) I finally got out of 4 low. The truck seems to be driving OK now. No weird noises and I can shift it in and out of four wheel drive OK. Think I did any damage? I've been driving four wheel drives for over thirty five years. Stuff still happens. Fortunately I have a lot of warranty left.

 

Nope, I doubt you did any damage. Toyota has too many electronic fail safes. Even wihtout those it would be ok. You can manually shift into 4lo on other vehicles at low speeds without stopping as long as the driveline is aligned though its not ideal. Just like shifting a manual transmission without a clutch, completely doable but not ideal.

 

I believe both gear sets in the t case are syncro'ed. Also, the OM says that we can engage 4Lo while moving at 2mph or less. I have never been successful unless completely stopped.

You should be just fine as @JoeCOVA noted. The 'puters keep the mechanicals safe, but slow.

Yes, 4Lo can be funky to engage or disengage. Find the way that works best for you.

 

Thing is the manual states that with an automatic transmission, you must be stopped, have your foot on the brake and the transmission in neutral to shift into 4 lo. (Yeah...I do read the manual.) I'm surprised the ECU let this happen. I did this once with one of my wife's automatic equipped Tacomas and the ECU would not allow the engagement of 4 low while moving. (Yeah...I don't always learn from mistakes.)

 

Any idea of why the procedure is different for trucks with automatic transmissions? With a manual transmission the manual says that you can be moving slowly when you engage 4 low.

 

From seeing different threads and experiences posted around here, the process to consistently engage it seems to vary a bit regardless of transmission. You'll see other folks say that 4Lo is finicky and caused difficulty to engage / disengage when needed. You will also hear a few relays clicking has the action happens, so there is some time delay that might not be sensed while the system is doing its thing. Just too many variables when you add in the driver, not even mentioning that sometimes folks need a bit of steering angle to get it completely in.

Myself, I also see the time it takes to engage and disengage 4Hi varies by a lot. It annoys me that I have to split my concentration on the flashing light versus feeling it with a lever.

This is why I said to just find a way that works, as if you were going to tell someone else how to do it if they borrowed your particular Taco.


My guess about the MT being able to roll is that we can do neutral and clutch in, so the T case is essentially free and disconnected from the input side. In an AT in neutral, the input side is still affected by the torque converter. Although, for my MT to reliably get it in and out of 4Lo, I need to be stopped.

 

I’ll never understand why they made 4WD look like the ac heat dial. That’s a bigger issue

 

Because most people are capable of reading and there is nearly 0 risk for damage anyways due to a wrong turn

 

It’s for cost savings

 

They should have put it on the other side of the steering wheel then. It's in a horrible location considering the knob is the same as the fan control.

 

If it kept flashing then maybe it never really engaged. I've spun that dial the wrong direction a few times. It happens. I think the computer is smart enough to block you from doing any harm.

 

Because the other guys complain when the knobs don’t all match.

https://www.tacomaworld.com/threads/toyota-why-you-do-this.495871/