Shift by wire transmission shift control system with park release

A gear shift control system, comprising:

• a first drive member including an electric motor;
• an output adapted to be coupled to a vehicle transmission and to the first drive member to be driven for rotation by the first drive member;
• a planetary gear set coupled to the first drive member and the output, and having three intermeshed gear elements including a ring gear, a sun gear and at least one planet gear, where a first gear element is coupled to the first drive member and is driven for rotation by the first drive member, and a second gear element is coupled to the output shaft for rotation with the output shaft;
• a second drive member coupled to a third gear element to drive the output shaft through the third gear element, wherein during a first mode of operation the transmission is shifted between park and other gears by causing the first drive member to rotate the output through the second gear element and the first gear element when a transmission gear shift is desired, and during a second mode of operation, the transmission is shifted by the second drive member which drives the output through the third gear element and first gear element, and wherein the second drive member includes a drive gear with teeth and the third gear element includes teeth meshed with the drive gear teeth so that rotation of the drive gear causes rotation of the third gear element.