ok you have three possible blinking lights in your civic si:1. if you are driving and reaching the rev limit for the gear you are in there is the rev limiter dot between the speedometer and the fuel gauge.2. it is you anti-theft system this dot is dark orange almost red it is between your speedometer and your engine temperature.3. it is the theft immobilizer on your stereo head unit this dot is red and blinks when you lock the car this is right beside the head unit and it's no obnoxious it's so idiots who might want to break into your car know that there's no point in stealing it because you need the radio-code to get the radio to function after it is disconnected from the power source.