Overheating Auto Gearbox

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This is a bit of a worry:-

http://www.caradvice.com.au/53489/to...w-road-test-2/

I do a lot of towing and a fair bit of 4WDing. Hope this is all sorted out by the time I upgrade.

Be interesting to see Toyota's response.

[electron55 Lurker Find all posts View Profile Close electron55]

Re: Overheating Auto Gearbox

Just read the story on the overheating auto gear box. My diesel auto gearbox has overheated twice now, the first time was the very first time I engaged 4WD, I was driving along a windy forestry track, light came on, I stopped and got out of the vehicle, I could smell a hot oil smell, 5 minutes to go out, 5kms up the road it did it again, it did another 3 times then did not do it again for the rest of the day. Toook it to Toyota, they could not find anything wront, IT showed no fault. I was not the first to complain about this, there had been a couple of other complaints already. Easter Saturday, it overheated again, this time is was only in AWD on a hilly forestry track, stopped to let it cool down, could smell a hot engine smell but not a hot oil smell as before. Havan't had it happen when towing on or off road, or hard 4WDriving. Off to the Toyota dealer today, will let you know of the outcome. Has any one else had an overheating problem?
Ron

[photoprado Avid PP Poster! Find all posts View Profile Close photoprado]

Re: Overheating Auto Gearbox

Worrying to have that sort of baloney happening in a brand new car that is supposed to be designed to cope with these kind of loads.

Good luck with it though!

Michael

[cobbo150 Lurker Find all posts View Profile Close cobbo150]

Re: Overheating Auto Gearbox

Hi Ron,

My car has had two episodes of A/T oil temp light coming on.

I have sent a customer feedback letter to Toyota Customer Relations Caringbah NSW detailing the exact circumstances of each episode. BTW ambient temperatures were 15c and 10c, so a hot day can't be blamed.

I suggest you send a feedback letter as well. As much detail as possible.

From what I have been able to work out, there seems to be a critical set of parameters, when bought together, will result in the A/T oil light coming on.

They are:
slow forward speed 20 to 40kph max
gearbox in auto or 4th......read as....let the auto box do it's thing and select the gear
steepish hill.......load on engine and transmission
RPM around 2000

There is without doubt, torque converter slip in the transmission, which results in fluid heat build-up, which triggers the A/T oil temp light to come on.

How to overcome the shortcoming of torque converter slip.......drive the vehicle in manual mode, which locks up the torque converter and keep RPM at or above 2500.

Because of road conditions, in both of my episodes (narrow road and blind corners) (bitumen roads BTW) I had no where to pull over. I was quickly able to workout what was happening, and changed the mode from auto (1st time) and 4th (2nd time) back to 2nd gear. This locked up the torque converter. After 30 to 40 seconds of continuing the climb, the A/T oil light went off. The weird thing is, the engine temp needle did NOT show any increase in temperature at all.

Knowing what I know now, I could travel both of these roads, without having the A/T oil light come on. Select a manual gear suitable for the climb and keep revs 2500 or above.

BTW, we tow a 2300kg full van and in 2500kms of towing, sometimes steep and hilly terrain , I have not had the A/T oil light come on. Why, higher forward road speeds and kept the revs at or above 2500rpm on the steeper inclines driving in manual mode.

I believe Toyota are addressing this issue and a software update will be forthcoming, to change the gearbox set points and fix the torque converter slip.

Our local dealer has checked out the car, with no faults showing up and a road test, reporting normal operation.

Hope this helps.

Cheers,

[electron55 Lurker Find all posts View Profile Close electron55]

Re: Overheating Auto Gearbox

Thanks for the info.
The parameters you describe are very similar to mine,
My speed was a bit higher, 40 to 60kph, box was in auto mode, driving up and down steepish forestry tracks, rpm about 2000.
The engine temp was normal, it was not a hot day.
The only other thing I was doing was using the gearbox in 3rd and 2nd as engine breaking on long down hills.
The funny thing is that for the rest of both days, I continued to drive exactly the same way and the warning light did not come on again.
My son is a Toyota mechanic, I will pass on your findings on to him.
Thanks Ron

[Geofft Lurker Find all posts View Profile Close Geofft]

Re: Overheating Auto Gearbox

I also spoke to aToyota service manager today about the over heating problem he asked all people with that problem to report it to their local service manager and ask them to pass it on to Toyota ASAP. Its the only way to have the problem fixed and ring Toyota customer service center phone via their web site.

[BrettT Lurker Find all posts View Profile Close BrettT]

Re: Overheating Auto Gearbox

Hi

I've had the same problem, under basically the same conditions you are describing. Had the car into our local dealer who is apparently the lead Toyota expert for A/Ts in Melbourne. They told me that it wasnt a problem with the A/T but a problem with the instrument cluster. They apparently cleared the error codes and stated that would fix it. I cant see how that makes sense after reading everyone elses posts.

I have also reported it to the Toyota Customer Service team who simply logged it as a complaint & told me to contact my local dealer. Despite the fact that I told them that the dealer had told me nothing was wrong with the A/T.

Oh well.. I hope they come up with a software update!!

Cheers
Brett

[Jase150 Junior Member Find all posts View Profile Close Jase150]

Re: Overheating Auto Gearbox

Guys,

Have now done almost 8000k's and some of that pretty tough driving, big dunes on soft beaches and deep bog hole crossings but had my very first A/T Temp warning light on the weekend.

Scenario -
Extremely steep and rocky hill (or actually mountain) climb - I'd estimate about 1km of 35+ degree incline
Not towing anything, apart from the full tank (87l) of fuel, my mate and his two small kids
Was in low range, held in 2nd (about 2000rpm or even less, wasn't watchin the tacho as I couldn't really take my eyes off the track)
A/T temp light came on and as soon as I found a clearing in which to turn around I stopped and let her idle
Light went out after a few minutes
No problem with the descent

Pretty annoyed at not making it to the top of the mountain and missing the view - a brand new $60k vehicle shoulda got up there without issue.

Will report to Toyota on my first service next week.

Not happy Jan!!! :evil:

[kavibaba Lurker Find all posts View Profile Close kavibaba]

Re: Overheating Auto Gearbox

Hi All

Just got back from Stockton beach where I spend the day messing around on the beach and dunes. Vx handled all the soft stuff with ease and I really had some fun. Even had a chance to use the DAC - a bit scary at first but works brilliantly down the dunes. Had the gearbox on D and glad to say I had absolutely no overheating issue(I did give it a bit of a trashing!) Torque and fuel economy was excellent compared to my petrol 120. So all up I am pretty pleased as this was my first chance to go offroad.

Day would of been perfect if we caught a fish! :lol:

[DavidK Lurker Find all posts View Profile Close DavidK]

Re: Overheating Auto Gearbox

150 kakadu diesel
I have had the overheating transmission quite a bit:
On the sand at Bribie Island: after 1k
On bitumen going up Mt Buffalo 12 degree celsius in the rain ! (moderate to steep uphill for 10ks)
On Bitumen after steep 3 km north of Dargo (15 deg celsius)
In the high country 6 to 8 times after 1 km very steep dirt tracks

Every time problem was solved by going to low ratio but that is not an option at 100 kph

Reported to dealer who initially said "Overheating not a problem - you just stop for a while !!!!" but later agreed it was a problem that they could not fix and they referred it to Toyota who replied to the dealer that they were getting "quite a few" complaints and are working on a fix which "could be months away"

That was 2 weeks ago & am still waiting for an update

Apart from that, a great car

[Geofft Lurker Find all posts View Profile Close Geofft]

Re: Overheating Auto Gearbox

Hello all

I just spoke to a couple of services mangers about the over heating, they said they just received a bullitin from Toyota that the auto will be rejigged so this doesn't happened. They both said that the light shouldn't come on and by re jigging it and reburning(????) the auto will fix the problem. One of the mangers said the auto is not over heating its just the light coming on when it shouldn't So next time your in for service ask them to repair it or give them a ring. The Bullitin came out today 23/4/2010. We will see!!!!!!

PSNew vehicles will have this automaticaly done but before picking it up check that they have fix it
Geoff

[Poppy Joe Member Find all posts View Profile Close Poppy Joe]

Re: Overheating Auto Gearbox

Good afternoon Toni,
Hi Folks
got my reply today how are you all getting on

thank you for contacting the Toyota Customer Experience Centre.

With reference to the condition you describe, Toyota Australia have recently developed a field fix. Fundamentally , there is revised A/T shift mapping to reduce Torque Converter slippage during high engine torque operation.

We would recommedn to contact your nearest Toyota Service Centre to arrange for this field fix to be applied to your Prado.

Regards

Craig Niven
Toyota Customer Experience Centre
Toyota Motor Corporation Australia Limited

[peter2904 Junior Member Find all posts View Profile Close peter2904]

Re: Overheating Auto Gearbox

Have not had the auto temperature problem and keen not to have it. I am towing the camper with the prado for the first time this weekend so keen to get the fixed.

Rang Toyota dealer today and asked about the mod. Dealer had not heard about the problem at all. They called back this afternoon to say Toyota had released a fix and booked my car in for Thursday.

For those SE Queenslanders, we are heading to the Kenilworth area via Maleny. That should give it a test.

Peter

[fish71 Lurker Find all posts View Profile Close fish71]

Re: Overheating Auto Gearbox

hi there all

Over the the long weekend we towed our 2 tonne trakmaster from the south eatern suburbs of melb up to Pyrenees, this involved the long climb up through pentland hills.

I towed in 4th all the way and pushed it up the incline with no problems allbeit the ambient temp was only 16 deg,

I take the advise never to tow in overdrive and thusfar it is a great tow vehicle.

at 5,000 klm almost up time to drop the oil and see what Toyota do with any remapping but i am happy so far

cheers

[peter2904 Junior Member Find all posts View Profile Close peter2904]

Re: Overheating Auto Gearbox

Had my ECU upgrade done on Thursday as planned. Have not noticed any difference on normal driving so far.
Towed the camper for the first time on the weekend (long weekend in QLD) without a problem using 4th. On the long hills the rev sat around 2500 without me doing anything. Not sure if that is normal or due to the mod.

Anyway really happy with the Prado towing. Felt stable whereas my previous vehicle (NP Pajero deisel auto) felt like it was getting pushed around a bit by the camper.