General Reversing Sensors - should they go off when wet?

[Doofer]

My reversing sensors beep like mad when I reverse out of the drive after it's been raining. Usually a constant beep or the "very close" beep-beep.

They usually work OK again after a good drive. I'm certain the rain is the cause - it can't be a coincidence.

I've never had reversing sensors before. Is this expected behaviour or a fault?

 

[s130]

Quite normal.

Least they warn early as opposed to late. The rest is up to the skill of the driver.

Of course you have got used to relying on the 'dry' reverse sensors allowing you to reverse to the mm before the constand beep one sounds. When in WET and driver disengaged mode the expected time period variable beep and that final solid tone my all be replaced by that "sinking crunch" experience.

 

[Doofer]

Is this normal for any car with them then?

I'll try drying them with a cloth next time, to see whether it's the water on the surface or if it's getting into the electrics.

 

[s130]

Yes dry them off on the surface and see if you still get the warnings.

I guess there are variations in sensitivoty between cars.

If in the rain/wet they are over sensitive but the dry OK, then depending upon the time between wet and dry will give an indication if this a water ingress situation.

Water ingress usually results in a long time to dry out. If the sensitivity lasts beyond a reasonable surface/joint dry out time then that might indicate water penetration into wiring / sensor.

If a surface dry off does not stop the beeping then you could try disconnecting one sensor at a time and see if the problems goes away. If it does then you may find that one of the four? sensors has developed an over sensitivty profile.

Another debug route on a very dry day is to use a plant water sprayer bottle and attack each of the sensors in turn (drying off between attacks) to see if one sensor is more sensitive that another.

Summary. A trail and elimination excercise