[Shaunbr]

I have a 2013 Nissan titan SL. Just noticed the other day that the transmission gauge was stuck on cold. Today it was 40° outside so I turn on the heat but no he came out. My question is are these two related and if so what is the fix?

 

[LUBECAKES]

I doubt it. The heat thing is usually that little servo on the heater hose near the battery. They get stuck, and can be repaired in some cases.
As for tranny temp, how far did you drive?

 

[Shaunbr]

I've driven 30-50 miles or so in the gauge never moved. To be completely honest I've never really paid attention to that gauge

 

[Jerry Helton 2]

Quick fix for heat. Pop the hood. On the passengers side firewall you will see your heater valve. Remove the 3 Phillips head screws that holds the cover on. With your Fingers turn the top gear all the way to the left. Presto! Now you have heat and still have AC. I fixed mine about a year and a half ago. It's all still good.