Always blinking security light - Or how much of a money sink did I avoid?

I looked at a second gen that had an issue which made me say "Nope! Not this one!"

With the fob out of the dash the orange light with the black key was on. Insert the fob, the light starts to blink. Hold the brake, hit the button, still blinking. Press the gas to start the engine. Still blinking. Shift to drive and go, still blinking.

Local Toyota dealer service department? Clueless. The used car dealer put a new battery in the fob, no change.

Aside from that, the car smelled of unsuccessfully removed dog odor so no sale.

 

But what was likely wrong with it? I don't need to look more, have a red 2009.