transmissio drops into 4lo at random

2015 4Runner - at random the 4lo, chk engine, Trak Off light goes on, the shifter resists moving, the cruise goes off, the real washer and wiper doesnt work. Then after a few days or overnight all just disappears. also the transmission actually runs in 4Lo. I've seen some older posts on this none that direct to the actual issue. Before I bring it in i could use some help.

 

The transmission doesn’t go into 4low, the transfer case does. Read the stored code and work from there.

 

Hi Albert. Welcome to the forum. So the title of your topic says that the truck is shifting into 4LO by itself. But in your first post you describe a bunch of lights coming on, including the 4Lo light. It’s basically impossible for the transfer case to shift into 4Lo “at random”. The transmission has to be in neutral, etc.

So can we assume that your transfer case is not shifting itself at random, and what you are actually reporting is lights on your instrument cluster illuminating at random?

 

https://www.4runners.com/threads/2015-4runner-check-engine-trac-off-4lo-light-on.24769/

https://www.4runners.com/threads/4lo-blinking-trac-off-hard-to-shift-won’t-shift-into.30549/

 

Yes all the lights go on with thd other symptoms mentioned and simultaneously the transmission goes into 4lo. At 70mph my tach would usually be 2k. When it switches to 4lo the tach is at 3k.

 

As stated in post #2, a 4R transmission doesn't have a 4lo. Only the transfer case does. So whatever your transmission is doing, it's not going into 4lo.

 

I may be wrong but can you even hit 70 in 4low?

 

I don't think so. I think I read somewhere on this site it maxes out around 50mph in 5th gear or something.

In any case the vehicle is not shifting into 4Lo at freeway speeds. the neutral safety switch is there for a reason. If that actually happened due to a series of glitches, the driver would DEFINITELY know it happened because the vehicle won't let you ignore the symptoms.

 

@AlbertG I’ve had dash light up in similar ways before maybe truck had gone into limp home mode and rpm’s increase cuz youre stuck in 2nd or 3rd gear.

 

I think you’re right, and I think 4lo caps in 4th gear

 

Are you sure it’s not S4? That’s not a massive RPM jump.

 

Sounds like the transmission is just downshifting a gear…5th to 4th. I would have the battery tested because that can cause a bunch of weird issues. Also read that code.

 

That does ring a bell.

 

I'm no expert, haven't used 4 low for years. But at 70 mph dropping into 4 low there'd be hair and eyeballs all over the windshield from the almost instantaneous drop in speed.

One thousand rpm increase? Baloney, there'd be pistons passing Artimis...

 

^This is what is going on. Transmission is shifting out of Overdrive (5th gear) to direct drive (4th gear). Mine does that all the time on the steep hills we have around here and that's how much the tach jumps up - about 1000 rpm. No possible way for the transfer case to shift itself into Lo Range at 70 mph - there would be gears and other parts scattered all over the road if that were to occur.

 

The shift to 4lo (light) and all the other symptoms happens at startup not while driving.

 

Welcome from Wisconsin! Did you try a code reader to check for codes? It may be a software/electrical problem, the code reader may help, also could be your 'actuator' for 4WD, another thing to try is disconnecting the battery to try a 'reset'. Good luck.

 

if it was 4lo you would be 6000+rpms and you would stop almost instantly and shit would frag. Sounds like its dropping into 4th gear from 5th not 4 Low.

 

No

 

Yeah. Stuff would detonate. If it could even enter that mode.

 

This thread is starting to remind me of another where we wasted pages and hours trying to help out a troll. We have a 2k to 3k rpm increase at 70 MPH when downshifting from 5 to 4, and dash lights illuminating on startup. Nothing is unusual

 

^ correct

At 70 mph in 5th mine with 33”s is about 1900-2000. 4th gear is about 2700-2800.

 

wouldn’t that be wild if the post is like a riddle written by a troll. sometimes trolls don’t return and don’t engage. OP checked-in this AM

 

Maybe it’s a bot designed to initiate engagement. But it’s a bunk post with moving goal posts.

 

Time to terminate the thread. Thanks all.

 

so what was the outcome or was this thread a complete waste of time?

 

The outcome: we now know that in 4LO @ 70mph we'll be turning between 6,000 and 7,000 RPM... unexpected left turn?