Funny this thread came up!
My wife alerted me to the same thing last night, and I had sufficient coolant as well.
I inspected the connector and cleaned it a bit, and the light wasn't on when I drove to work.
I didn't do the thorough silicone cleaning necessary, so I expect to see the yellow glow soon.
2009 ML350 (84K) - Family vehicle
2001 CLK430 Cabriolet (71K) - Wife's car
2005 BMW 645CI (124K) - My daily driver
2012 Mustang V6 (60K) - Daughter's car