The low coolant light is in the coolant recovery jug and usually requires the jug replacement because that is part of it ...
as far as check engine light that is proably a differnet problem unless your low coolant light is correct and it has run hot ....
the computer has reconized a problem and id trying to tell you somwing is wrong ..........I forget if ya can clear the code with a 2000 by disconnecting battery ...try it and go from there
call dealership about coolant juf it might be a recall by now because I know I MUST HAVE REPLACED A COUPLE OF HUNDRED OF THEM OVER THE YEARS
25 YEARS GM TECH WITH MASTER GM
bg
March 2006