Originally Posted by fudge_brownie
I wanted to install one but found out ahead of time that there are no codes or no sensors for transmission temperatures on my 2003 4Runner....
You may want to check out the Toyota 4-Runner Forum
. There are others with 2003 4-Runner (and older) who have reported that they are able to program their Scan Gauge II to read transmission fluid temperatures with their 4-Runners. Keep in mind that is not always a built in function of the Scan Gauge to read this code, but requires that the user program in the correct information that allows the transmission fluid temperature sensor to be read.