Replacing the wheel speed sensor isn't a hard job. You should be able to do it in under an hour.
First, here is a link that shows how it is done in general. Use this as a guide.
Here are the directions specific to your vehicle. The pics below correlate with these directions.
2005 Chrysler Pacifica V6-3.5L VIN 4
Vehicle Sensors and Switches Sensors and Switches - Brakes and Traction Control Wheel Speed Sensor Service and Repair Procedures Front
WHEEL SPEED SENSOR FRONT
1) Access and remove front brake rotor.
2) Disconnect vehicle wiring harness from wheel speed sensor connector (Fig. 1).
3) Unclip wheel speed sensor connector from frame rail outer reinforcement, then open routing clip on reinforcement and remove cable (Fig. 1).
4) Remove screw fastening wheel speed sensor routing bracket to strut assembly (Fig. 2).
5) Open routing clip at knuckle and remove wheel speed sensor cable (Fig. 3).
CAUTION: Prior to removal, clean area around sensor head to help prevent contaminants from entering bearing when sensor head is removed.
6) Remove screw fastening speed sensor head to hub and bearing (Fig. 3).
7) Remove wheel speed sensor from hub and bearing.
1) Apply bearing grease (supplied with part) to sensor head shaft and O-ring.
CAUTION: Ensure that sensor mounting surface on bearing is clean before sensor installation.
2) Push sensor head into mounting hole in hub and bearing and align mounting screw hole.
3) Install NEW mounting screw (Fig. 3). Tighten mounting screw to 20 Nm (15 ft. lbs.) torque.
4) Place wheel speed sensor cable grommet into routing clip at knuckle and close clip (Fig. 3).
5) Attach wheel speed sensor routing bracket to strut assembly (Fig. 2). Tighten screw to 13 Nm (115 inch lbs.) torque.
6) Clip wheel speed sensor connector and routing clip to frame rail outer reinforcement (Fig. 1).
7) Connect vehicle wiring harness to wheel speed sensor connector (Fig. 1).
8) Install brake rotor as well as all components necessary to access it.
9) Verify that wheel speed sensor cable is properly routed and not coming into contact with rotor or other moving parts.
10) Road test vehicle to ensure proper operation of the base brakes and ABS.
I hope this helps. Let me know if you have other questions.
Take care and God Bless,
Images (Click to enlarge)
Wednesday, March 10th, 2021 AT 8:58 PM