step-by-step guide on how to monitor transmission temperatures

[m_and_m]

In the video (link) of auto-mate showing how effective it is at reducing the transmission temperature, I use the Ultra-Gauge to display the temperatures (Pipe and Pan oil temp).

One of the most common questions I get asked is how to setup an an OBD2 reader to monitor the transmission temperature.

Attached is an article I wrote that provides an understanding of why you should monitor the transmission oil temperature, plus a step by step guide for setting up three of the common OBDII solutions:

1. UltraGauge MX
2. ScanGaugeII
3. TorquePro

The article is applicable for the Mitsubishi Pajero (NS, NT, NW, NX), Challenger (PB and PC), Triton (MN, MQ and MR), and Pajero Sport.

[Edit 11Apr23: updated for Paj Sport and MR Triton]

cheers Marshall

[Pwoffey]

Very nice, thanks for this Marshall

[BruceandBobbi]

Hey Marshall.

What is the "normal" operating temp for the Jatco box?

[NTBenny]

Very nice Marshall, thanks so much. I've been wondering lately as to whether I could monitor pan temp as described in your Youtube clip but using the Scangauge. Was planning on messaging you but you've beat me to it.

Cheers,

Benny.

[m_and_m]

Hey Marshall.

What is the "normal" operating temp for the Jatco box?

There isn't a specific normal temperature, rather a range.

It's too hot if above 125degC, as this is when the oil starts to deteriorate.
Below 45 degC they don't change gears quite as smoothly.

Generally around 65-75 degC is an ideal temp to have the transmission. A bit higher or lower is still fine though.

[BruceandBobbi]

Thank you.

[Ian H]

Excellent work Marshall, thanks.

[old Jack]

It is also worth remembering that once the load has come off the unlocked torque convertor, after climbing a steep hill and descending the other side of the hill, the ATF temperature can continue to rise because the torque convertor is not locked up when there is not accelerator input. When the torque convertor is unlocked and the vehicle is "coasting" the ATF does not circulate through the ATF coolers so the ATF is stationary and sitting in a hot torque convertor. This is done to decrease fuel consumption but at the penalty of overheating the ATF. So the ATF takes a long time to cool down, particularly in very hilly country and especially when towing.

Lockup Mate keeps the torque convertor locked up even when there is no accelerator input, this allows the ATF to circulate through the ATF coolers after the load has been reduced and results in ATF temperatures dropping rapidly. Auto Mate works slightly differently as it unlocks the torque convertor when coasting down hill, however there is a special feature that locks the torque convertor up to provide downhill ATF cooling if the ATF is over 85C. Marshall really has thought of everything!

This is just another reason why the MM4x4 Lockup Mate and Auto Mate products are superior to other torque convertor lockup kits that are on the market.

OJ.

[_jp_]

This is a great set of instructions.

I have been running a Scangauge since getting the NW an programmed the ATF with the following MTH 00010001FFD0, which was posted on the forum long ago as being correct. It looks reasonably accurate to my untrained eyes. I see your instructions quote the MTH 00010001FFCE for a marginally different offset.

Given your in-depth knowledge of how the Aisin trans operates, I was wondering why there is a difference in the MTH.

[Onsan]

...Auto Mate works slightly differently as it unlocks the torque convertor when coasting down hill...

Is that correct?
I ask because that was the reason I set the AM8 to lock up from 3rd, I found coasting towards the lights or a stop it would pull you up a abruptly as it was staying locked up in 2nd when coasting.
It still locks up in 3rd coasting but the engine braking isn’t as severe on the higher ratio.



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[m_and_m]

Is that correct?
I ask because that was the reason I set the AM8 to lock up from 3rd, I found coasting towards the lights or a stop it would pull you up a abruptly as it was staying locked up in 2nd when coasting.
It still locks up in 3rd coasting but the engine braking isn’t as severe on the higher ratio.
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In the Challenger version it unlock when in DRIVE and coasting. This is because the JATCO is particularly 'rough' when downshift with the TCC locked.

The Pajero version is different, and keeps it locked hence you noticing the downshift more.

I'm curious about your experience above. Setting '3rd' only has an effect when in SPORT mode.
In DRIVE, it doesn't tend to coast in 2nd, as when it goes below 30kph the trans is switched to factory DRIVE operation which goes from 3rd to 1st (avoiding 2nd completely).

[m_and_m]

This is a great set of instructions.

I have been running a Scangauge since getting the NW an programmed the ATF with the following MTH 00010001FFD0, which was posted on the forum long ago as being correct. It looks reasonably accurate to my untrained eyes. I see your instructions quote the MTH 00010001FFCE for a marginally different offset.

Given your in-depth knowledge of how the Aisin trans operates, I was wondering why there is a difference in the MTH.

It depends on how people determine the offset to deem a value as 'correct'. There is no difference between the NT,NW and NX AISIN transmissions that require a different offset to be used.

Some people determined the offset through trial and error, trying to get the offset to match other temperature sensors when the car has been cold soaked.

I used a Mitsubishi MUTT3 to display the actual temperature the then determine the correct offset from that.

FFD0 vs FFCE is only a couple of degrees difference, which a negligible difference in terms of the way we use the displayed temperature.

There is a lot of confusion around the correct offset to use because it does vary across models, which is also why I wrote the guide.

[Onsan]

M_and_m, I’ll go and double check by setting it back and taking it for a spin.

When I first installed it, it was very noticeable, pulled you up a bit aggressively, it also faulted and triggered a check engine after a couple of days use. Error code was for lock up not releasing so I changed it after that. It has faulted again (froze, no active control) since but only briefly before being power reset and did not trigger a check engine light.



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[m_and_m]

M_and_m, I’ll go and double check by setting it back and taking it for a spin.

When I first installed it, it was very noticeable, pulled you up a bit aggressively, it also faulted and triggered a check engine after a couple of days use. Error code was for lock up not releasing so I changed it after that. It has faulted again (froze, no active control) since but only briefly before being power reset and did not trigger a check engine light.

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Yes, a few cars have thrown a fault within the first couple of weeks of use. It's not common, but has happened. The adaptive learning soon gets used to the lockup kit and thereafter it's ok.
At what speed is the aggressive pull-up as it changes down gears? Not 30kph is it?

[Onsan]

Getting back to you on this.

Changed the setting back to lockup from 2nd and have been driving it for a bit over a week. It is releasing fine once below 30k/hr just like you said, if you really try you can get it to pull you up when it holds 2nd above 30k/hr, but only deliberately. So all is good, I've not had any other engine faults pop up, so I guess it may have been just part of the adaptive learning you mentioned. That may not be limited to the car either.