WARNING: This page is about a different car, the 2003 Pontiac Sunfire and 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Transmission Does Not Shift into One Gear Diagnostic Table (Steps 1-6)
Courtesy of GENERAL MOTORS CORP.
Fig 2: Transmission Does Not Shift into One Gear Diagnostic Table (Steps 7-9)