Diagnostic Aids
WARNING: This page is about a different car, the 2002 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.
The sunroof limit switch soft stop signal circuit can cause the sunroof glass to hard stop past the soft stop open position, if it were a short to ground or a faulty limit switch. Refer to CIRCUIT TESTING and WIRING REPAIRS in Wiring Systems. If the circuits test OK, an intermittent or poor connection can also cause the sunroof not to operate normally. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS in Wiring Systems.