Gen 1 2004 Tacoma UltraGauge MX Transmission Temperature

Works like a charm.

 

$25 on Amazon gets you the same thing.

 

So I bought a MX for the trans temp and alarm feature and compared it to my OBD2 dongle with OBD Fusion. Trans temp was 10 degrees higher on the app over the UG. This was after I parked and unhooked the UG and waited for the App to load all the data.

Now I’m curious just how accurate this is and if it can be trusted.

 

Since it is an unsupported function, it is only as accurate as the equation used, which I don't trust anyone has calibrated or tested.

The best way to watch trans temps in a 1st gen is to add an additional sensor somewhere (pan, cooling lines, check port, etc) and wire it to a physical gauge.

 

I was suspicious this was the case as mine has routinely been showing in 220’s/230’s after normal driving. Fluid has about 30k on it and still looks and smells great, so I feel like it’s definitely reading high. Fluid is getting changed out here soon while installing a cooler, may thrown in a physical sensor while I’m at it.

I’ve kind of used it more as a trend watcher, like pulling on long grades or lot’s of stop and go. I can see the temps climb or drop well before watching the dummy gauge on the dash.

 

Unsupported by Toyota or UG? With the OBD fusion app I was able to purchase the advanced package for a 04 Tacoma and trans temp was part of it. I can’t see why this is an issue for UG specifically. Even Scanguage has an option for trans temp. I suppose they just don’t care to put in the effort?

 

Unsupported by Toyota over OBDII. Sure, we can access the location of the sensor over OBDII, but since it isn’t officially supported I never trusted the number the ScanGauge reported.

Also, the refresh rate/bandwidth of the 1st gen ECU over K-Line is really slow.

Like I said, the best think you can do is wire up a new temperature sending unit, install it somewhere to read the temps and hook up a dedicated gauge.

Until someone does some verification (on their own truck) with a real calibrated temperature measurement of the fluid and compare to OBDFUsion/UG/SG, it’s just giving you a relative range to watch.

Basically, if the torque converter is unlocked, trans heats up. Sometimes a lot depending on the other variables.

I moved on from my 1st gen for many reasons, but one was the A340F.

 

Wow that is high. For me it was reading low. I’ll have to do more testing comparing the UG to the dongle and OBD Fusion.

I bought the UG on a whim being frustrated with issues that OBDfusion had. I guess I jumped the gun. I worked fine, just annoying issues that probably won’t ever fix.

Curious if we could get someone like OBD fusion or Scanguage to Supply their data for getting trans temp then plug it in to the UG.

Either way I’m having a hard time understand why UG won’t do this. I’d be willing to pay more, as much as a standalone temp sensor and gauge costs, just to have it all in one place with alarms.

 

Just couldn’t wait for OV to finally step in huh? Lol highly double that’ll ever happen.
I’ve been seriously considering moving on as well for the same reasons. But I’m going to have to wait until it makes sense. What are you in now?

EDIT: never mind. Saw your description.

 

As others stated. The pan temp sensor or cooler line t- fitting is the way to go. Just completed the install considering a write up

 

I went with the auto- meter phantom 5757 to closely match the stock gauge. T fitting with 2 3/8 males barbs and a 1/8 npt to 3/8 reducer. Spliced into the cooler line then had to fix an extra ground to the t fitting to an engine ground. System is working. With a small cooler pulling a 1500lb boat wet my highway temps on flat land have not exceeded 150 on highway and 170 stop and go traffic

 

I’m just going to ride with it. I’m getting pretty much the same temps as you @Toyotadilly. And it’s close enough in line with the app to not worry too much about it.

really, I only need the trans temp sensor to know it’s not getting 200+ in conditions when it shouldn’t be. It’s at least good for that considering it works in the way A trans temp sensor normally would. Fairly normal temperatures under normal conditions and increasing/decreasing on the right conditions.

 

Subbed

https://www.tacomaworld.com/threads...ansmission-temperature-pid-for-torque.686658/


Adding this thread to the transmission cooler page .Once members start monitoring their temps , they are going to figure out that a trans cooler is needed .
Here is a cool write up with all installations as well as pictures
https://www.tacomaworld.com/threads...l-toyotas-write-up-with-many-pictures.526283/

 

Received my UG mx 1.4. worked perfectly with the code mentioned here in the thread. Thanks to who posted the code, cheers!

 

@gearcruncher ive been following ur recommendations for awhile. Going with larger cooler soon looking forward to seeing the numbers. Also comparing fan with no fan I know it can block air flow. Possibly upgrading to a spaal.

 

The grounding of the t- fitting took the longest. I think an all aluminum radiator is in the future. Also curious about rear axle temps

 

lots of great info in these posts. Figure I'll add mine. 01 double TRD Limited warranty Snugtop.
I installed the blue digital gage at the bottom of the dash. Mounted sensors on Tran fluids in and out lines and engine coolant with switch to select each. Then I attached a 'k' type thermocouple to the end of the trans dipstick and monitored the sump with a Fluke meter and recorded min / max Temps.
New radiator, fan clutch, shroud, and coolant.
No aux cooler
Took a trip pulling a 3700lb travel trailer (9000lb total wt) over steep N. Calif passes.
Engine held 170 to 180 every where.
Trans out maxed 230 for brief pulls, also heated up low speed through town. Always recovered quickly. Normally would be around 170.
Trans in =10 to 30 degrees cooler.
Sump temperature ranged between the two . But went higher, from residual heat?, when shut down.
The temp out rose quickly and significantly when the converter would come out of lockup.
At the end of the trip fluid color and smell appears as did at the start.
I'm convinced that the auxiliary cooler is needed for this kind of load.

 

Is anyone familiar with when the torque converter locks up in the auto transmission?
I deal with steep mountain passes fairly regularly, so I'd to make every effort to not put the trans through unnecessary work.
Should I be looking for a certain speed/rpm or is it a simple case off turning off Overdrive?

 

Lock out torque converter with o/d off. That simple. And yea ur correct.

 

@Vaushaus add transmission cooler