Transmission temp gauge on 1st gen Tacoma

Are there any write ups on installing a transmission temp gauge in a 98 Tacoma someone can lead me to? I believe I have the OBI 1 not sure though. I’m hauling an in bed pop up camper that weighs 1300lbs loaded and I don’t want to over heat tranny when in mountains. I do have a trans cooler installed.

 

If I'm not mistaken automatic transmissions have a line that connect to the bottom of the radiator thus cooling the automatic transmission. I know this because when I installed the radiator on my manual transmission I kept that bottom port capped.

 

I've read a lot of people using Scan Gauge (about $140 on Amazon), but I do not have one. Also, several have said the Ultra Gauge ($much less) can be programmed to read trans temp.

 

OBDII was required from '96 up if memory serves.

Real time tools can only read what the ECU outputs. If the vehicle didn't out put trans temp, one of those tools won't get it done. You probably determine that by going to a site like ScanGauge and looking for what they call X codes for your year, brand, model. No code? No output to be read.

Your second choice is to install a traditional sensor in the trans cooler circuit and montior with an auxillary gauge in the cab. A lot more work, some risk of leaking if not done right or damaged in the future, and a one horse show. But effective.