You really need a code reader to tell you wich sensor is down, but if you put the car in reverse with ignition on and listen to sensers in the bumper you can hear them clicking. If no noise, senser has gone down, but if water ingres it wont show a fault which is where you need a code reader, if painted sensers fitted sometimes you can see the paint is bubbling where water ingres so worth looking out for.
Gaz, September 2007
