My son wrote off our 06 Accord so we just picked up a used 2016. I have a few questions: 1)There is a button that I think is for the tire pressure sensors but when I press it nothing happens. 2)The seller has a separate remote for an aftermarket auto start but the strange thing is that I used the factory remote to autostart the car when the door was open by some remote key sequence that I can't seem to reproduce. 3)Is there a PDF or online manual I can access for this car?

 

I'm not sure about the accessories on your accord and how to work them. I think you can access the owner's manual on honda's website if you register your car on their site.

 

I'm still waiting for Honda to fix my account to login. In the meantime, I've noticed that three wheels have a weird large valve stem cap but the fourth wheel has a regular green cap. Any idea what that would they would be?

 

Take a look at the big caps. I've seen caps that have a pressure indicator. A green caps usually means the tire was filled with nitrogen instead of air. The advantages of nitrogen over regular air are negligible in my opinion.

 

Update, after going to the dealer I found out that the weird looking caps are just caps and have nothing to do with the TPMS. The TPMS goes by the wheel speed sensors.