The speed sensor is located on the drivers side of the transfercase, you will see a sensor with a connector, that is your sensor.
On my 2000 Grand Cherokee Laredo 4.7 are 2 sensors. They are both located on drivers side of transmission. The one close to bell housing is input shaft speed sensor. The one at end of transmission is output shaft speed sensor. My input sensor went bad but replaced both. Both sensors are the same. Fairly easy to change out. About $47.00 each at dealer.
Yes
Mounted atop the transmission tail shaft.
The 2001 Jeep Grand-Cherokee has a 4-speed automatic.
The 2003 Jeep Grand-Cherokee has a 4-speed automatic.
The 2002 Jeep Grand-Cherokee has a 4-speed automatic.
The 2004 Jeep Grand-Cherokee has a 4-speed automatic.
You're probably talking about the input speed sensor and/or the output speed sensor (if your model has one). They are about $20-$30 a piece, it's a cheap fix.
The 2010 Jeep Grand-Cherokee has a 5-speed shiftable automatic.
The 2013 Jeep Grand-Cherokee has a 5-speed shiftable automatic.
The 2014 Jeep Grand-Cherokee has a 8-speed shiftable automatic.
The 2008 Jeep Grand-Cherokee has a 5-speed shiftable automatic.