using aftermarket temp. sensors on 7427 ecm's

[brian617]

In the first 4L80e (1991) It used a thread in trans temp sensor. I would think It would be the proper sensor for what you need.

https://www.sonnax.com/tech_resource...identification

[1project2many]

just a thought..... if i leave all the tables the same and use a bench setup to determine what temp the ecm "thinks" 160 degrees is. (lets say when the probe is at 160 degrees the ecm thinks it is at 300 degrees) couldnt i simply set the parameters in the fan mod to turn on at 300 instead of 160? i am only using the ecm to control the motor, the transmission is stand alone, and i am not even using TCC at this time. and if i do use tcc in the future, it will not be controlled by the ecm.

Sure, you could do that. And it may work well. I'm thinking the transmission control code is fairly complex. So what happens if you disable all the transmission stuff and that inadvertently turns of the trans temp fan control? I'm not saying it will, just asking what if? What if there are other side effects? At 300 degrees transmission temperature the ecm may be decide to greatly reduce spark advance to reduce torque at the converter. Your solution may be best. But would a simple temperature switch perform the same function allowing you to select a "manual transmission" configuration in the calibration?

honestly the coding is way over my head, i want to learn but that is going to be a long process lol... i dont know what the different commands are much less how to set up the tables into a usable format. i am very thankful for you guys that have pioneered the way for guys like me to be able to tune our toys without knowing the ultra technical coding stuff, we only have to learn the highly technical tuning stuff lol..

Understood. If you decide you'd like to create new tables for the transmission temp sensor there may be help available. I'd also look into the solution suggested by Brian. It seems like a viable option.

[grumbolt]

Thanks Brian! I'll look into that.

Good insight 1project2many! I hadnt thought of the other issues!

[grumbolt]

WOOHOO looks like this sensor is what i needed!! *
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** with a little more research, it turns out this packard temp sensor does not have the same temp curves as the oem sensor.
** in the amazon description it says " Equivalent to AEM 30-2012 " the temp chart for that sensor is in this pdf: https://www.aemelectronics.com/files...sor%20Data.pdf
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https://www.amazon.com/Packard-Tempe...796728&sr=8-63
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this sensor is the direct replacement according to rock auto... just my luck it is 3 times the cost lol

*** removed link due to it being the wrong part as well****

now just gotta wait for it to come in so i can test it! i will post back with the results of the testing when it comes in.

thanks again guys!


EDITED DUE TO MORE RESEARCH SHOWING I ORIGINALLY FOUND THE WRONG SENSOR!

[grumbolt]

it seems that the screw in temp sensor for the 700r4 is internal and discontinued/superceeded by the plastic temp sensor that is part of the wiring harness..
looks like i will just set the transmission fan up so that if the engine is running, so is the fan, and buy an aftermarket gauge to install on the transmission and bolt to the dash so that if it overheats i can stop and let it cool down..

the part i ordered from rock auto / carid had the entire trans harness with the sensor as part of the harness.
i am yet to find a oem gm temp sensor that will thread into a 1/8 npt port... i guess my other option would be to break the line going to the cooler and install a T fitting and use a ECT sensor.. im pretty sure that is a 3/8 npt..