What does it mean if the 'S' on the dashboard of a 1991 Honda Accord LX keeps blinking?

I am having the same problem. The "S" light on my 91 Honda Accord is staying lit up. I am worried about it, so anyone, please help. the vss is located below the thermostat housing ...has a three pin connector attached to it...this controls your shift, speedo,cruise control and it costs 60 bones at www.1aauto.com just type in speed sensor on their search thread Before buying a speed sensor, try resetting first. Before starting the car, push sport button on the console gear shifter, start and let it idle for 30 to 60 seconds, turn off engine and restart the car. Try several times. If they dont do the fix, buy the sensor