High Transmission Temp Warning - Stalling in 4lo

Thanks for all of the input everyone. Going to see what I can do to get my hands on a new CPS in case my current one fails while I'm in the middle of nowhere. @0uTkAsT I'll check in on your build thread every now and then to see if you find a decent aftermarket tranny cooler.

 

cooler and fan install http://www.tacomaworld.com/forum/2nd...n-install.html

 

Happened to me on Sunday doing the water fall at black bear pass...
Worth taking the truck in?

 

OP same thing happened to me. I was doing an obstacle course in Hollister and I was stuck in one spot and truck was at an extreme angle (I believe close to 35 degrees) for little while with engine running. All of sudden I see High transmission temp sign flash and truck shuts it self off automatically. After less than 2 mins I cranked it back up and truck fired right back up without any issues.

I believe it was due to 2 main reasons. First, truck was at an angle and all of the oil probably moved away from the sensor. Second, these trucks have clutch driven fans. Since the truck was at very low RPM, the fan didn't engage and cooling system didn't kick in.

I have done plenty of offroading with extreme angles after that and never had that problem again. I just keep an eye on my temp gauge at all times and I do rev the engine often to engage the fan clutch to keep everything cool.

 

I had the same thing happen in my old '17, backing up a steep driveway. Truck stalled, high trans temp warning. Fired it up after a few seconds and it ran fine. I took it in, the dealership acknowledged the engine had stalled. But could find nothing wrong with it.

I would take it in just to get it on record, in case it happens again after the warranty period.

 

I didn't read the entire thread, but it has happened to me twice. Both times going up a steep incline. I'm pretty sure its from two foot driving holding the brake and trying to ease up the hill. Pretty sure the transmission doesn't like that.

 

Sorry to bump. This happened to me too, though oddly trans temp and pan were only like 170F or so. First time this has ever happened. I was sitting for a few min like this. It did it twice and flashing trans temp high as well as low oil pressure. Each time started right up fine. Hasn't happened after that climb.

I have no clue what it was.

 

I had this happen as well. I immediately cycled thru my ScanGuageII to find the trans temps and found it to be 194. Not even as warm as the engine temp. This almost happened at a terrible time. It was shortly after climbing Whale Bones on the Rubicon. If it had happened while I was climbing, it could have been pretty ugly. I was perplexed when I saw the temp. I was on fairly flat ground climbing some decent sized boulders that are in the trails right after the Whale Bones when it did it. I have low (5.29) gears and lockers and was NOT pushing hard at all. VERY slow and controlled. That said, I was driving with two feet. This happened two more times on the trail that day. We had to go as far as letting the truck sit for a half hour before attempting hard sections. The next day, I tried to drive with only one foot. Much harder sections and longer/steeper climbs. Never overheated AND saw temps that were in excess of when the truck shut off. Same the following day and ever since. Zero issues. However, the trans temps gets well above the 194 when I am driving on the highway climbing steep hills. Never has given me the over temp. It was also VERY unnerving climbing tough sections and wondering if it would shut down.

I think, the Toyota computer does not like the fact I was driving with two feet. Gentle increase of RPM and regulation of speed with the brake... I am almost convinced of it. I now have my thermostat pinned. I am looking into a cooler. But, the temp was not out of line in my opinion. In theory it should get at least very close to the coolant temp since they share the radiator.

Any other opinions about this being the computer hating two footed driving style while crawling? My temps say it was fine, computer said it was not. What gives?

 

It's not a trans temp issue, its anti-stall feature for rolling backward while in 4-lo. I do it from time to time and can duplicate it. You can duplicate it in 4-hi as well but much harder and anti-roll kicks in.

It protects the drivetrain from doing what its not supposed to.

The computer is confused and shuts down the transmission to protect it because you aren't supposed to move backward in D

 

This has happened to me and others when using crawl control for extended periods of time. I imagine if it doesn't come on during normal use, there's probably nothing to worry about.

 

Thanks guys. Makes sense, I also used 2 feet then, maybe we used 2 feet cuz it was rolling back which caused issue like @JoeCOVA mentioned.

 

Hey Joe. Thanks for this bit of info...
I at at first thought no way as I was using two feet specifically to keep my self from rolling back. After thinking about it more, maybe I was rolling back though, at least that is why I started two footing it. It is hard to understand it being an "anti-stall" feature when it literally shuts the truck off. Rolling backwards down something gnarly with no power brakes or steering seems anti-productive. To duplicate do you literally just put it on a steep hill and let it roll back?

Thanks as this is the first thing to me that makes sense even though it doesnt. Stupid computer knows best...

 

Is this a 4wd ONLY specific issue, or can it be replicated in 2wd? Reading through this thread makes me have nightmares of stalling and going into the lake on a steep boat ramp. I've always 2 footed to gently move up the ramp instead of 1 footing/unintentionally gunning it and just spinning, and I've coached my wife to do the same. I can't imagine how she might would react if the truck stalled trying to pull the boat out.

 

Odd that it triggers something with the trans temp but like others have said i wouldn't worry about it. My 2nd gen has done this from time to time stalling on a steep incline trying to bump over a ledge or something. Just start it back up and good to go lol.

 

Might be a 2wd feature as well but you'd have to be on a pretty steep incline for it to happen. Reason i say 2wd is my truck is a converted 4wd so it doesn't have the factory computer system for 4wd and it has done it to me in 4wd on a couple of occasions but granite the times i need 4wd is the only time ill be in a situation that steep.

 

Saying dont worry about it is very easy to do if you are in some easy little hill or maybe even a boat ramp (sorry, not to undermine, but this is a much safer spot...). If it happened to me on Whale Bones, it would likely cause a roll over or at least a smashing destroying crash at the bottom. I can assure you I DID worry about it. Seriously worry about it. I shut down my truck and waited for temps to drop before I did numerous hills because of it. It was in my mind all the time when my truck was precariously perched on three wheels off camber at the top of a rough climb.

That is why I was extra interested in what Joe described. If I can replicate it, I can feel better about how to avoid it and not get myself in a spot that is too dangerous. There is no option to not worry about it when you are doing what I was doing and many others do to an even greater extent.

 

Very well said. I agree with you, not worrying about it is the dumbest idea, and removes all personal responsibility for recognizing a problem and addressing it. A boat ramp doesn't compare to a severe off camber, one slip up, roll-over scenario, but in either case, I wouldn't want my wife in the driver's seat if a known issue of 2 footing causes stalling and could potentially put her underwater. At the end of the day, both could be catastrophic if the driver couldn't save it after a stall, and we're both in search for duplicating the issues and learning from it. I'll leave the 'not worrying about it' to someone else.

 

Please see bold text above. I do not know what whale bones is since i live on the other side of the country but when i t happend to me i was about on a 40* incline in an off camber situation. Im not talking about a small hill on the road or at the boat ramp man. I actually wheel my truck. Anything off road iis dangerous. You could rip a break line and loose all pressure non the less. As soon as mine stalled twice in the same 40* incline place it wasn't that hard for me to keep me from rolling backwards by stomping on break. My foot stays glued to that area anyway when im on steep inclines. if your trans temps are actually getting that high it has probably got to do more with a cooler issue than anything your truck is doing stalling. I would look into that if i was you. Its happend to me on numerous occasions and ive seen it happen to others. Offroading is a dangerous game especially if your doing wilder stuff. Like @JoeCOVA said "
It's not a trans temp issue, its anti-stall feature for rolling backward while in 4-lo. I do it from time to time and can duplicate it. You can duplicate it in 4-hi as well but much harder and anti-roll kicks in.

It protects the drive train from doing what its not supposed to.

The computer is confused and shuts down the transmission to protect it because you aren't supposed to move backward in " These trucks weren't built to do serious crawling or even extreme inclines so its just a draw back of owning a Tacoma. Thats why i said i wasn't worried because its happened to me a handful of times in pretty dangerous situations and ive never fallen off a cliff or gotten hurt because of it as long as you know its possible in the situation your in and your ready for it.

 

OK... Please see what is bold above...

As already stated, mine is NOT overheating. I mentioned that I monitor it with a gauge. After my measurement, others comments and personal experience, I believe it to be something more computer related.

I am not here to fight about what is something to worry about or not. In my case, it is a potentially very serious damaging/hurtful reality. Others may find it to be an easily disregarded annoyance. I am now hoping to find how to replicate the issue, with the first hand experience of others, so that I can become more knowledgeable in how the truck's systems work so I (and others) can use their truck as they wish to in the environment and conditions they wish (from boat ramps to rock crawling) without interference from the wise and safety freak computer.

 

I think to be clear, when the vehicle shuts off from this you dont lose your ability to apply the brakes. When this happens I dont come crashing off an abostacle and down a trail, in most cases i don't even roll back off the obstacle, I just restart and go again.

From a road or boat ramp perspective you would apply brakes like normal and simply restart the truck.