low coolant light
 

I have a question
I have a low coolant light on a friends 2001 Buick Regal
He added about 3/4ths of a gallon of coolant ( It is about 95 degrees for the last week here in N California.)
and he says the light is still on....
I am Guessing that the Computer needs to run those 50 mile diagnostic loops??? My Ford takes 3 sets of 50 miles before clearing some error lights ( Unless You reset the light with a Mechanics diagnostic plugin thigamajig...)

any Help will be welcome....

Thank You:)