Parking Sensor

[jsj24uk]

Hi people. I seem to have a parking sensor on the back bumber, far drivers side that seems to think that there is somthing there when there isn't and guess what, it is an intermittent problem. I have made sure it is clean, polished it, buffed it, but it still seems to think that somthing is there. It's a right pain when your parking and you have a solid tone and nothing is there. The car has 11 months Lexus warrenty on it so I shall be taking it back to be looked at but does anybody know what it might be?

Many thanks.

[Giblet]

could be just faulted, i've had a similar issue and only thing i could see was very direct sunlight / reflection from something. Not sure why, but always seemed to happen on an extremely bright day.

[Anuj]

ive recently had this problem with my 04 430. it was the middle front sensor. i took it back 2 lex last week were they sed they were dirty and they had cleaned them. they said if it carries on they need to take the bumper off. i am positive it is not due to dirt but i noticed it happen when it had been raining..