1st generation 2006 key fob dead bay

I have 2006 tundra limited and went to use keyless entry key fob and truck didn’t unlock and no clicking noise I pressing key fob a few times and got a low pitch noise out of truck. So unlocked with key and locked back with key , later on was outside and rear lights were stuck on so disconnected battery and waited an hour and reconnected battery , at that point truck wouldn’t start battery probably is dead but rear lights were still on. Any thought ?

 

Yup to that ^^

After, first take battery to parts store and have it tested. Rule that out totally before proceeding with startup diagnostics.

Second, if your truck came with immobilizer, as Sequoias and some Double Cabs did, you should replace your remote battery.