Advice needed - 4WD activating on its own.

I have a 2021 Platinum CM and over the past 48 hours, 4WD has decided to turn on without any warning. Today, it felt like I got rear-ended as I was driving around 25mph. It has about 1200 miles on it. Anyone ever heard of this happening?

 

No idea but I would get it into a dealership ASAP before something breaks…

 

Is the knob still in the 2HI position when 4WD is activated?

 

Yes, even when switching back to 2wd it remains.

 

Let me clarify. You’re driving down the road, suddenly you feel the 4 x 4 activated, you look down and the knob is in the 4 hi position? That won’t happen on its own, you must be doing it without knowing. Now if it is engaging 4 x 4 without the knob ever being touched or turning from the 2 hi position, then you definitely have a problem. That knob will not move on its own. But if it is engaging 4 x 4 without the knob moving, then you most likely have a short somewhere.

it is common for 4 high to be difficult to disengage or engage out on the dry pavement. The truck likes to be moving in a somewhat straight line to engage/disengage.

 

Sorry, should have explained better. The knob was still in 2WD, felt like I got rear-ended. To assess the issue I was switching it back and forth, and when going back to 2WD it would not switch back.

 

Yeah that’s messed up, take it back to the dealer. Something is shorting out in the system somewhere. It should never go into 4 x 4 without that knob.

 

There was a thread recently very similar to yours, but his 4 x 4 knob was “magically” moving to the four high position. Pretty sure he was accidentally reaching down to adjust the air conditioning and grabbing the 4 x 4 knob. Easy mistake to be made when your mind is on something else.

 

I take it your dash is indicating you're in 4HI right? If so, sounds like the 4x4 ECM is getting a faulty reading from the 4x4 switch.

I agree with everyone else, take it to the dealer and make sure it's documented.

It shouldn't feel like you got rear ended switching into 4HI though, if you were driving in a straight line. If it tried to switch to 4LO, well....

 

This^^^ Twice now that this has been posted for the same issue from different members..hmmmm.......coincidence?

 

Stop and reverse a bit in a safe to do so place and that should help it disengage

 

Ya, definitely not even coming close to, I have owned a 2017 before this and never had the issue. Also, the car is going into 4, not just reading it - you can feel it. However the 4HI just blinks, which is also interesting....

 

But yes, dropping off at dealer tonight.

 

Maybe you have rodent wire damages

 

Please keep up updated on this one. Its crazy and my curiosity meter is in the red.

 

Our tundra has this. We would turn it on and it would try to go into 4LO we just moved the switch back and forth. You probably just have a bad switch and you can get it replaced. Hope this helps.

 

Funny enough, faulty actuator...

 

Let's see what happens over the next 200 or so miles to be sure. Personally I am skeptical a little bit.

 

Update, not the actuator. The car is still at the dealership after 3 weeks, waiting for an answer from Toyota... not ideal. Everyone is stumped.

 

Your truck is haunted

 

Sounds to me like the right tech for the job is on vacation or quit and they are trying to buy time. I just don't see it being that difficult to figure out. A switch, a few wires, and an actuator or two actuators really. Current either flows or it doesn't, actuator either actuates or doesn't. If I am not mistaken there is also a vacuum hose involved, haven't really studied the whole assembly yet though. Regardless, an average mechanic who knows his way around a multi meter should be able to diagnose this issue in less than one day. WTF

 

They want the truck back, so they could sell it for more money

 

Tell them it's time to order a transfer case and a switch, and give you a loaner. F*** the dumb excuses.

 

Yes, defnitly a bummer. Apparently now waiting for tech from Toyota corporate to answer question. Same dealership is adding Suspension/wheels/tires, cant do that until problem is fixed. Playing the waiting game.

 

Three options for this: Bad switch, bad actuator, bad wiring.

 

Update: Toyota HQ said it was an ECU problem. ECU was changed out. Still did not fix…. Going on 1 month at dealer starting tomorrow.

 

Are you making payments? If so, I would say talk to a lawyer soon. Or let them think you are..

 

Time to take it somewhere else

 

Curious also. I was in 4H last week, everything was good and all the sudden the 4L and 4H started blinking. Then i pulled over to the side. Turn the switch back to 2H, then took off again switch it back to 4H it was fine. Then on my way back home it did it again. I m bringing it to the dealer on my next maintenance and ask them to check it out.

 

Same problem I had.