And I watched my traction bat temp all the time. I was frustrated at finding some guideline as to where the "safe" temp for longevity. I still don't know other than cooler is better and I trust the Toytota Engineers, who don't say schit about "safe." On the trip I found the highest temp at 93 degrees. Ugh, simply because that sounds high. Ambient outside was 82. Inside was 86. (It wasn't THAT high by simple comfort...I don't know where the inside sensor is.) So after fidadling around with the AC and turning it on, then off, then remembering to switch it to "outside air" duh....it came down to 82 degrees. It really need positive cabin air pressure to force air through the rear seat air vents. That was the biggest change. My conclusions...... Either DONT install the Scan guage.... Or don't install the code for traction bat temp... Or don't worry about it ... Or drive yourself crazy like I do worrying about high temps....93 seems high...dunno if it is. Any other thoughts? Why doens't Toyota give any guidelines?