I bought the iCarsoft LR V1.0 this week in the expectation that it would read the fluid temperature in the auto gearbox. I checked with a couple of suppliers and both assured me that it would. However I cannot find ATF temperature anywhere in the menus and the supplier clearly as no idea as he simply refers my query to iCarsoft 'technical support'. Their suggestion was to do an automatic scan and 'try to find the oil temperature'! Not very impressive technical advice.

Has anyone got this model of OBD scanner and found a way to measure ATF temperature with it.

It otherwise seems like a decent piece of kit for not too much money but I’m not sure I’ll keep it if it can’t do the one thing I bought it for.

JLR manual says :

Fluid Temperature Sensor
The fluid temperature sensor is integrated into the internal wiring harness within the transmission. It detects the fluid
temperature in the hydraulic pressure control circuit and transmits a signal corresponding to the temperature to the TCM.
The TCM monitors the temperature and provides smooth gear shifts across a wide range of temperatures.

Is it possible that the signal from the temp sensor only goes direct to the TCM and is not available via OBD. I wonder if you have to interrogate the TCM - only guessing as I cant find the ATF temp with my Torque Pro.

But Ive come to the conclusion that the ATF level is not critical - just get the engine to normal working temp.

Does anyone know the thermal expansion of ATF ? And be able to calculate much the ATF volume would vary with the ATF being 10C above or below the required 60c Jules

In relation to the auto gearbox the only reference to temperature is to the oil temperature sensor and this gives this value. I’ve no idea what it means.

Jules,

You may be right. I’ve been looking at a number of other OBD scanners and none of them seem to offer ATF temperature so it may not in fact be accessible just via OBD. Even the highly rated GAP IID doesn’t seem to do it.

AWTF-80 SC holds 7 ltrs being overfilled by half a ltr not going to be a problem

If that’s the case, why the instructions for filling it in a precise manner at 60 degrees?

Only saying with 7ltrs in transmission a extra 1/2 ltr not going to be alot in the bottom of pan. They also say aw1 is sealed for life .so why do we change fluid only saying .we can go on and on . But if you take your motor for fluid change at a town garage I don't think they monitor the temp of ATF .

Land Rover specify an ATF change at 10 years/150,000 miles.

I’d say you’re quite right that a town garage won’t monitor the temp - that’s why I wouldn’t take it there.

So I think I’ll just go by what Land Rover say. I suspect they know a bit more about it than you, with all due respect.

Getting back to the original problem - does the iCarsoft measure ATF temperature - it’s looking increasingly like it doesn’t. One OBD manufacturer said to me quite clearly that their device doesn’t measure ATF temp as it’s not part of the standard OBD2 live data set so if that’s the case, then no ordinary OBD scanner is going to do it. GAP have initially said theirs does but I’m still querying that’s with them.

I might just have to use SDD (if I can find where the ATF temperature is!)

I changed my atf fluid earlier this year and used the Gap iid BT tool to monotor the ATF temperature. Whatever it was measuring it it worked for me!

That really sux ........one other possibility is to tap in a correctly calibrated temp sensor and wire it to a damn aftermarket gauge mounted internally. But, SDD will likely do the trick! Good luck Simon J!



^^^Looks like this guy, is using Volvo vida dice software through the OBDII port.

JonMs wrote:

I changed my atf fluid earlier this year and used the Gap iid BT tool to monotor the ATF temperature. Whatever it was measuring it it worked for me!

Simon J wrote:

Land Rover specify an ATF change at 10 years/150,000 miles.

)

Maybe you could attach a temp sensor to the ATF cooler pipe leaving the gearbox. Somewhere need the RED arrow.
That may give a good measure of ATF temp inside the gearbox.



I bought several of these a few years ago to control heaters in my greenhouses - work great

https://www.ebay.co.uk/itm/220-240V-Digita...Sw441bZRjw

I also use them to monitor and control temperature of my honey before bottling.

Im going to tape the sensors to the ATF pipes next time I get a chance and watch the temp change against time.
I should really get out more  Jules

Last edited by jules on 1st Nov 2019 9:56 pm. Edited 2 times in total

Reading up on EOBD standards, it would seem that while engine coolant temperature must be provided, engine oil or gearbox ATF temperature is not obligatory. The gearbox sensor does indeed, as Jules has suggested above, provide a signal to the TCM to adjust the behaviour of the box depending on the temperature of the ATF. But it does this by varying a signal current to the Powertrain Control Module, the varying current being produced by a heat sensitive resistor in the sensor. So one would have to access the output of the sensor and then find a way of converting that to degrees C (or F).

I did buy an inexpensive Infrared non contact thermometer and perhaps this might be the easiest way of estimating ATF temperature although one would then have to factor in the emissivity of the alloy casing!

There are lots of inexpensive 12v temp controllers on ebay

eg

https://www.ebay.co.uk/itm/DC-12V-LED-Digi...Sw8e5a7Z5R Jules