Electrical gremlins:
A monsoon / mini hurricane... I had to drive thru pounding rain, multiple flooded road areas with 1-2 feet of water in them, although I tried to drive slow(er) and around the worse spots, but had to try to keep up following a friend in the dark who seemed pretty delighted to be spraying 20 foot of water with his jacked up new Tacoma.

Next morning:
Key fob won't open doors (red LED light illuminates on key though).
Trunk won't open. Nothing works.

I manually open driver door with key. ALARM hammering horns lights for 2-3 minutes. Repeat cycle several times.
Putting key into ignition or starting car won't shut up alarm, I'm thinking key batteries are weak now. I wave keys all over dash and under steering wheel where I think the chip sensor is. Doesn't help.
I finally pull the under hood horn fuse.

Now just before this I drove the car a little in parking lot to see if it will shut up. Nope. Keeps squawking.
Perhaps it's right after I pull this fuse (??) but then the AT trans is stuck - won't shift.
So of course I am driving it now manually unlocking the shift lever.

Also, after one dry 5 mile drive or less the alarm is not coming on AND the key fob now works like normal. 2 days and about 30 drives and that is working fine, like the problem was never there.

Also, when alarm was going only one front DRL type lamp was lighting up. Now with key suddenly working, and with the car alarm not going, but ignition 'on' / running, I see both DRL lights are in fact illuminated. Weird right? Why would only one light up for alarm but now they both seem ok?

BUT shift lock is still locking up AT lever. AND I also now have a VSA CEL light on the dash. Has never been on before. Pushing the VSA button on dash does nothing at all.

I have also noticed sometimes the AT indicator light on the shifter goes out.
I've only had this car for about 2-3 months... and found out after the sale it was almost certainly a repo.
It was not treated well, that's obvious from the looks, interior, paint and other indicators.

Separately:
It also has a whumwhumwhum... low pitch audio noise always when driving. Even in neutral with engine off it's still there.
I swapped my TSX wheel and tire with each the two front wheels, thinking that might be a bad tire, bent wheel, bad balance but no difference. Just had car inspected and based on my verbal he thinks it's a wheel bearing.
It might just very slightly change tone and be a little more when wrenching wheel hard to passenger side. No change turning super hard to driver side / left.

 

Stop by a parts store and have them scan for codes, since you have a CEL.

Post the actual code on here and not the description. Codes start with the letter P and have 4 numbers, like P1234.

 

Ok, but maybe I mis wrote that. Or maybe not. It's the VSA light that is illuminated in the dash. Not sure that's an actual OBD code or not.
Somehow this is all tied into the same problem.
I'm also trying to find a wiring diagram next and see what else is snuck on that horn fuse I pulled.

 

Well. I fixed this myself.
Would have been nice to know the brakes were tied into that under hood fuse.
Since the key works again and the alarm is not going haywire I simply re-installed the "horn / stop" fuse.

The VSA traction light instantly went off on a ignition re-start. The AT shifter lock problem is gone, and I would imagine my brake lights work again.

No one here knows that the Horn fuse is related to all that?