Low coolant light

After draining just a small amount of cooling out of the radiator to work on pulling the throttle body I now have an intermitent low coolant light coming on......The system is full of coolant........Any fixes...I'm thinking its the reserve sensor.......

The sensor may or may not detect low coolant after draining below its level. If four or five drive cycles (coolant heats up to 160, allowed to cool to ambient) it still doesn't go off, I'd replace the sensor.

Make sure system is bled.