Auto Transmission Cooler 150 Diesel

[johnb Lurker Find all posts View Profile Close johnb]

I have recently purchased a new 150 series diesel and use it for towing a 5.1 metre caravan. Do I need to fit a transmission cooler? I have heard reports of the AT light coming on when towing. My mate had a software update by Toyota to his electronic control to change trhe setting of the lght. I am in Melbourne, and am interested if any one has done this and where it was done.

[David Condie Lurker Find all posts View Profile Close David Condie]

Johnb,
I have just had the very issue. I towed my 2 tonne caravan all the way across the Nullabor ( from Victoria) . I got to ALbany and the High Temp AT alarm came on. The outside temperature was about 15 degress.! What i found was that thevehicle was spending a lot of time in 4th gear ( and not changing into 5th). So I have done 2 things .
Firstly manually changing up to 5th gear whenever possible and also had the Bunbary Tpyota dealer "update the ECU". Which means that they increas the temperature at which the alarm comes on at.

I have not put in a Transmssion cooler yet.
If ot comes up again on my way to the Kimberlys I will be forcwed to add the Transmission cooler.

Regards
Dave C

[rvator2 Lurker Find all posts View Profile Close rvator2]

Hi John B,

I raised this issue back in January 2010, just before we took delivery of our GXL D4D auto. The old threads were lost when the forum was upgraded.....I was cobbo150, then.

Our dealer service manager confirmed that there was an oil cooler fitted as standard to the 150.

As we had one of the early 150's to arrive late Jan 2010, we were one of the first to discover and report the auto high temp alarm coming on. This happened twice (Snowy Mtns area), and not towing the van.

I documented a full and detailed report, which I sent to Toyota. The quick fix was.....keep rev's 2500 or higher, when going slowly under load up hill, and light will not come on. it worked for me. Problem was torque converter slip, due to staying in to tall a gear.

Around April, Toyota had an upgrade for the transmission ECU, which fixed the proplem. The dealer should do the upgrade FOC if it has not already been done.

We tow a tandem van which is 2300kgs loaded. Never had a problem towing the van with the high temp AT alarm light coming on.

So far we have towed the van about 15000kms over all sorts of roads and the engine temp display never goes above normal, even with a bug screen over the upper and lower grill.

We are more than happy with our decision to go with the 150.

If you are towing I would highly recommend upgrading to the Gravel Rush GR150 mudflaps. They really do a good job on protection of car and van.

Cheers

[maxjj Senior Member Find all posts View Profile Close maxjj]

so I am confused, one of you changes to the highest gear asap, the other tries to keep the revs 2500rpm or above. So which is it?
Or does changing gears manually, ie in sportsmode get rid of the slip?

[smakb Advanced Member Find all posts View Profile Close smakb]

I had the upgrade to the ECU software, but I beleive the main fix is that it keeps it in a lower gear more, which keeps the revs up and helps with the temp of the trans. Toyota also recomend manualy selecting the gears when under heavy load. Apparently the problem was changing up to early. Have not had the light come on since having the software upgrade.

[discoveraus Member Find all posts View Profile Close discoveraus]

Hello all,

My comment is "Read the Manual". The manual is very specific that all towing must be in Sports mode 4th gear. The manual also prohibits using Cruise Control while towing.

These instructions let the engine rev harder with less torque converter slip and reduces the number of high load gear changes which occur with the cruise control selected. If you want your gearbox to last " RTFM".

regards

Ross

[Davad73 Junior Member Find all posts View Profile Close Davad73]

^^^^^ as above, well said. As with any transmission never tow in over drive gear.

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

Discoveraus has hit the nail on the head. The manual says to use S mode when towing.
Now re the transmission cooler. I have always fitted auto transmission coolers to all of my tugs. I asked our dealer about fitting a transmission cooler for towing and was told we do not recommend fitting of non-genuine equipment. As Toyota does not make one they don’t do it. So much for keeping your vehicle genuine and Toyota service.

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

Hi there,

My first post, and also my first 4x4. I followed a mate up to the top of Mt Coree (Brindabella National Park). I wasn't towing anything, but had 5 POB. About 100m from the top, I got the AT Temp warning. Some of the climb is fairly steep, but mostly rocky (with a bit of mud thrown in)... So some of the gear and RPM solutions mentioned above aren't necessarily suitable.

I have read the manual (twice), and just wanted to know if these were conditions I was supposed to be in Low Range? I didn't find it too strenous on the car, but then again, my last car was a falcon... so what do I know.

Also, I bought the car new in April. Is the ECU a by request upgrade, or should a new car already by flashed?

Thanks in advance for any constructive assistance.

Regards,

Nads.

2011 Prado VX

[saskia Lurker Find all posts View Profile Close saskia]

Now re the transmission cooler. I have always fitted auto transmission coolers to all of my tugs. I asked our dealer about fitting a transmission cooler for towing and was told we do not recommend fitting of non-genuine equipment. As Toyota does not make one they don’t do it. So much for keeping your vehicle genuine and Toyota service.

Cyclone in this diagram http://www.toyodiy.com/parts/p_G_201...html?hl=32923K it shows pipes running from the transmission to the "radiator area" and the wording is "Automatic transmission oil cooler tube". So from this the vehicle is suppose to have a transmission cooler. Here in South Africa Toyota has indicated that somehow the transmission coolers are removed at the factory before shipment, and they (Toyota RSA) are now refitting them on request.

[150gxl Member Find all posts View Profile Close 150gxl]

^^^^^ as above, well said. As with any transmission never tow in over drive gear.

Yes indeed, read the manual because there are other manufacturers who say DO tow with auto in "D".

[discoveraus Member Find all posts View Profile Close discoveraus]

Helo Nadsy,

Talk to your mate and he will tell how to drive gently in a 4x4. Generally the Toyota auto is set up as a highway cruiser and delivers excellent fuel consumption by holding onto higher gears as long as possible. When you work it harder I suggest that you use sports mode and keep the revs up above 2500 rpm. Play with it a bit by selecting a lower gear even when the revs are over 2500 rpm if the engine sounds like it is pulling hard. I often find that changing down a gear will not increase the revs at all but reduces torque converter slip significantly.

On my steeper driveway at home I can climb in 3 gear at 2500 revs seemingly easily, but pulling it into 2 gear it stays at 2500 rpm and the speed does not change at all, pulling it into 1st cause a revs increase to 3000 rpm. The auto will stay in 3 gear if left to itself. Obviously 2 nd and 1 st are easier on the transmission and will reduce torque converter slip which would cause the gearbox to heat and the temp light to come on.

Drive on some steep stuff with the windows open, you can hear the engine and transmission talking to you when it is working harder. Play with the gear selection to work out how it can sing, dont let it scream or groan. Windows up, radio on, passenger talking and in D are all problems when the going is tough.

regards

Ross

[Foxy49 Junior Member Find all posts View Profile Close Foxy49]

Hi guys, I automatically added a cooler before I did anything else .People have had their SUV'S reprogrammed because of the light and I have been told from my dealer with the cooler if no red light comes on then it's not necessary to flash your vehicle. I have a 20k BTU unit with a filter and temp gauge situated before the radiator .I tow a 19.5 foot Coramal with my shortie and I have no trouble with over heating even on the hottest day.I would definitely go for a cooler before I get the vehicle computer flashed .They (Toyota) will be reluctant to re flash after a cooler has been fitted back to the standard flash (Settings) Also it would be silly to tow for any length of time in D. You only have to read the manual which makes a lot of sense to look after your bands in your Tranny because the biggest enemy of Trannys is HEAT. Hope this can help Cheers Foxy

[barajak Senior Member Find all posts View Profile Close barajak]

The ECU update raises the temp at which the light comes on. I tow a 2 tonne van and find the Prado TD auto is a Gem of a tow vehicle in S4, sit on 2100 to 2300 rpm and it is quiet and strong and the transmission remains locked up. One of the reasons I fitted the Scangauge was to have a digital readout of the coolant temp as heating in the auto will heat the coolant. This will give you early warning of a heat buildup so you can slow down and/or use a lower gear before the light comes on. I have heard of two Prados that have had intercoolers fitted and under extreme 4WD conditions have broken the hose and trashed the transmission. Given the problem can be overcome with driving style, I would never fit an intercooler, not worth the risk.

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

Thanks discoveraus. I'll give it a go.