Low Coolant Light Question

I have a 2001 Tahoe. For the past few months, my Low Coolant Idiot Light has been coming on when I idle for a short time, especially when I am running both the front and rear air. The temperature is fine, and I am not low on coolant. I think it's probably just a faulty sensor, but if anyone else has any ideas they would be appreciated.

Mike

the coolant sensor is going bad, and you have to buy the whole tank assembly with sensor in it to fix it.