2012 tundra button underneath passenger side?

Looking at a 2012. Wasn't sure what this button type bolt is. Anyone know? Had a cotter pin wedged in it but not correctly placed.

 

Is it near the transmission? Looks like the thermostat bypass for the transmission. You push it in and put a pin in it to bypass the thermostat during a transmission fluid change.

6:36 minutes.
https://youtu.be/cNu3feOLXxI?si=PfRhnI_K34nZ1mFG

 

Does look to be so. I think the previous owner must of just left a cotter pin slightly inserted for some reason, maybe to avoid using a new one? Thanks.

 

Probably forgot that B in there... This is the main reason I take a 2nd look once I'm done with any maintenance, for stuff like this... When you're done with the world, and you're ready to set it ablaze, lol...

 

Some people pin the transmission thermostat open for "extra cooling" while towing.

Personally believe it would only serve to warm the fluid more slowly, but would not prevent it from reaching the same peak temps.

Probably doesn't make much difference

 

There is also not a specific cotter pin. One just bends a paperclip.

 

That's a spring clip from the brake pads.

 

Haha. It sure looks like it!

...maybe I'm the only one who still has/uses paperclips