What is that blinking dash light when the car is off?
 

I have stared at that light trying to figure out what it is.

When the car is off a red dash light blinks. What is the light and what is it for? Wondering if it is just some alarm dummy light.

security system is armed

it means there is something terribly wrong. I suggest you take your car to a rocket surgen right away.

It indicates that the car is detecting the RFI chip in the key. Scion calls it an engine immobilizer system- the engine won't start unless the chip is detected. You probably have the key in your pocket- I keep meaning to check out how far away it can "see" the chip, but it's at least 15 feet or so, maybe more.

Do you know if some stock Toyota 86 FT don't have an alarm installed ? I don't have the panic button on my key.. and I tried to enable the alarm by unlocking the door keeping unlocked pressed but the light keeps flashing.. Does the ECU have to be flashed for the alarm to work I mean the factory default alarm.

Its not an alarm, just the immobilizer. The flashing light pretty much just means its doing its job. It looks for the chip in the key to make sure its the right one for the car. You can actually cover your fob in tinfoil and the car probably wont start.

As they all stated, its the security system. The flashing indicates its functional, most cars have it these days. Slow pulsing red light you will notice on most locked cars.

I was going to post, then I realized i already did 3 months ago LOL