WARNING: This page is about a different car, the 2003 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Diagnostic System Check - Loss of Coolant (1 Of 3)
Courtesy of GENERAL MOTORS CORP.
Fig 2: Diagnostic System Check - Loss of Coolant (2 Of 3)
Courtesy of GENERAL MOTORS CORP.
Fig 3: Diagnostic System Check - Loss of Coolant (3 Of 3)