One problem related to brake disc caliper has been reported for the 2002 Nissan Xterra. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2002 Nissan Xterra based on all problems reported for the 2002 Xterra.
Purchased in November of 2006 and in may 2008 as I was attempting to stop at a traffic light in the city only doing about 10 mph. The wheel jerked really funny and there was a noise coming from the brakes. Upon attempting to go my car wouldn't pick up speed and was making a rubbing noise. Limped into garage where they showed me my calipers were locked up. Had both calipers, brakes and rotors replaced. October 2009, driving at 55 mph, started smelling burnt rubber smell, check engine light came on so I pulled over to have it towed. Thought it was overheating even though gauge did not indicate that. Garage stated I needed a new brake line so had it replaced and on the way home I began smelling that horrible smell again so I decided to take to another garage where they showed me my caliper was locked up just enough to heat the rotor up. Had calipher and brakes replaced. April 2010, just from past experiences I knew what the rubbing noise and loss of power meant. Sure enough driver's side calipher was locked up. Had calipher, brakes and new brake hose put on. July 2011, yet again my caliper is locked up. So as I am typing this its back in for the usual. In almost every instance there were no warning signs of failure until it became extreme. I contacted Nissan but they stated its the usual wear and tear. I have never heard of replacing calipers every year under normal driving conditions.