A/T High Temperature Warning Pulling Offroad Teardrop?

Hello gang, this weekend we towed this from Blue Ridge, GA to Knoxville, TN (about 132 miles):


No issues and towed like a dream. All highway.

Backing up the hill into the driveway (very steep, but short), I got an A/T High Temp Warning message. I shut the truck down 2 mins later once I fully got into the driveway and turned it off.

Started it back up and the warning was gone.

Thought this was strange as the truck has about 2k miles on it... and the teardrop weighs about 2,300 lbs dry.

Curious if you guys had any thoughts.

 

Did you have it in Tow/Haul mode? I also wonder if 2k miles is past the break in period that Toyota recommends no towing?

 

I did have it in tow haul mode. Don't know about break in question

 

Per the manual <500 miles no towing, <1,000 miles keep it under 60mph, I think. Over 1,000 good to go.

 

Ok, so I'm good on the break in period... I drive like a grandpa btw... so that's another oddity about it...

 

The combo of the steep hill and using reverse likely caused the temp to spike. Next time throw it in 4LO to give the transmission a ton of help. Might be worth pulling a sample of fluid to make sure it is still bright red and doesn't smell burnt. My recollection is the transmissions have to be quite hot (230-240??) for the light to come on.

 

Thanks kind of what I was thinking... that I should have used low range... it hasn't be an issue in my tacoma or FJ.. the tundra is heavier than the tacoma but not the fj.

I read that the light comes on at 300 degrees.

 

It must have already been pretty hot leading up to this and the hill out it over the top. No way it would overheat just from one small hill.

I would consider getting a scangauge or similar to monitor your trans temps.

 

I’ve seen a few posts about trans overheating in reverse. I think there was one a few weeks ago and had deja vu reading this post. I think it was just you going in reverse.

 

Does anyone know if this setting can be changed with Techstream? This seems like an insanely high temp for the warning light to come on.

 

That was in another post on the forum (300 degrees). I haven't validated that yet.

 

I would check your tranny fluid or have the dealer change it under warranty or something. I got the A/T light on my 4runner once and the fluid was totally fried by then and the torque converter went out a year later. At a minimum I would drain a few drops and just smell it. I can't believe the Tundra is such a bitch it can't back 1000lbs up a little hill.

 

I don't believe it's 300 degrees. It's around 225 for 1st Gens. 300 would be insane.

 

My 2010 was around 240 I think. 300 is very high.

 

The 2019 models to not have auxiliary oil coolers like earlier models. Not sure what Toyota was thinking. I have an 019 and it is very easy to heat up the trans oil (Torque Pro app) especially the TQ converter. While backing my 400# trailer into my back yard, I had to do some back up/pull ups to get it where I wanted. I quickly hit 235 on the converter oil and about 210 in the pan. The only heat sink you have is the 199 deg. coolant and heat flow through the case and pan. I pull a 1400# load on interstate a lot (was in K town Saturday as well). Pan runs about 210 - 215 at highway speed in 5th gear. My older model stayed at 199 in 6 gear with same load. Will change fluid often.
bc

 

Want to see the reason behind this. O drive like granny but want to know if our "cadillic" can hold up to the GMC. If not I'll never be able to live it down

 

reverse is a shitty gear to be going up a hill (happened in my 2000 Silverado) ... the boy suggested to put in in 4low - reducing the gearing by 1/2...and up it went - no problem...

Give that a shot next time you need to reverse up a hill

but with that light of a trailer...shouldn't have mattered

 

If that truck don’t have a tranny cooler on it , GET ONE . I can’t believe that they would not do that. There not expensive.
I gone reverse in mine mine (2016) for over a mile with 5000 plus, never had an issue.

 

Problem is, they don't have a takeoff for the oil on the case. It is blocked off and requires installation of the thermostat like the older models have. About 200$ part and not an easy install. I have lifetime warranty on drivetrain and would void it if I modify.
Thanks,
bc

 

My 2019 runs 220 all day long with no trailer. And no more cooler lines to do a flush or add a aux cooler. So its down to just draining 4qts from the pan. Pretty damn stupid of Toyota.

 

Sorry bout that, not a gear head by any stretch . It’s so odd though. Even my new Ford Ranger came with a tranny cooler. I thought it was standard equipment these days!

 

So did I! I did not find out until I got home with it.

 

Anyone get a 2020 yet and know if they have them? A truck that’s supposed to pull 10k should have a trans cooler.

 

220 is hot for just normal use, even my 2017 I had with a trans cooler ran 186 unloaded and I was 200-215 loaded or towing spike 220-225.

 

Yeah I had a 1st and 2nd gen Tundra, Fj and Tacoma all lifted with big heavy tires and none of them ran this high of tranny temps just putting around town. I will do a pan drain at 5k and send it in for a analysis to see if the trans will live a long life. On my taco and fj the trans overheat light didnt come on till 300F verified with scanguage. Both overheated while wheeling on long trails at slow speeds in middle of summer.

 

Yeah my wife has a 2012 Tacoma and the trans runs like 167-176 in the hot months on that truck, I haven't been able to get it over that. Post up your analysis results from the trans fluid when you do that, curious to see what they say.

 

If your warranty permits (or is running out) you might look at getting someone to install the thermostat takeoff and a cooler. My dealer would not give a yes or no on warranty if I modify.
bc

 

Your original posts about this whole lack of cooler is what made me keep a log on the trans temps, thanks for posting about it. My son has a 08 and I pinned his cooler open and pulling a heavy ass rockcrawler his temps are lower pulling grades than mine driving around town.
I will do it myself when i get out of the drivetrain warranty. I have been scheming on even running a secondary closed cooling system so I can try and keep the coolant as cold as possible. It would not be hard to bypass the tranny from the engine coolant. A nice electric water pump a big ass cooler with efan and it might actually work.

 

The secondary cooling would allow you to put the hoses back to stock if it didnt work out. Retro fitting the thermo would definitely be a lot harder to revert for warranty work.

 

I would be very interested to see that system.
bc