Parking sensor

[Jagturbo1]

Parking sensor not working on my xj8 l 4.2 350. 2005 can anybody help please.

[Jimbov8]

Front or back ?

A code reader will tell you which is defective.

[Darren J]

To find out which one's failed, start up engine, get somebody to sit in car with foot on brake (firmly!) and test front ones in D and rear ones in R. Put your ear over each sensor. You should hear a faint clicking on each if it's working. One that's not is the culprit. If you get a long beep for a few seconds when putting in reverse the  it'll be a rear one that gone.