Park Lock Solenoid
WARNING: This page is about a different car, the 2004 Hummer H2. However, it is still accessible from the selected car via links, so may be relevant.
The park lock solenoid is a safety device that prevents an inadvertent shift out of PARK when the key is in the OFF position. The key must be in the RUN position to release the park lock solenoid. The system consists of the park lock solenoid. With the ignition in the ON position, voltage is supplied to the park lock solenoid. The park lock solenoid energizes through a permanent ground unlocking the shift lever. With the ignition in the OFF or ACCY position the park lock solenoid de-energizes and locks the shift lever in the park position.