ESP & Tyre Pressure Warning Lights on, Easy fix?

Hi, new member, I have a 57 plate VRS Diesel. Today both the ESP and Tyre Pressure Warning Lights came on, they don't go back out. I had Hunter 4W Tracking done a few days ago and ended up having to have both track arms replaced as the mechanics spent 2 hours trying to move a couple of bolts! I drove the car for around 100 miles before the light came on.

Am I correct in thinking that this combination on lights means the Wheel Speed Sensor is broken? Is that an easy fix if it has? I will check on my next day off to see if a connection has come loose, where will I find the connector for the sensor.

Oh and sorry for another question will the ABS work while the sensor isn't?

Many Thanks for any advice.