High Pitched Sound Possibly From Parking Sensors

[steve955]

Morning Jag Enthusiasts, I occasionally get a high pitch sound that last for a bout 5 seconds, This can be when in traffic or when I put the car in reverse. I guess it could be to do with the parking sensors, they seem to be working but I tend to turn them off by the switch overhead to stop the noise. Is there a way of checking them out?

[Montana5]

Moved your post to here Steve as its electrics, you will see there are many posts relating to Parking Sensors in this section, my own first look suggestion is that you could have dirt trapped inbetween the gaps in one of the sensors, or the paint has blown on one of them which causes a bounce back of the signal.

Doug.

[steve955]

Over the last few months the sensors have stopped making irregular high pitched noises. I have not done a thing but everything seems to work as they should, electrical glitch perhaps?.

[J44EAG]

I regularly get this issue on my X350. Same symptoms, usually in the Winter when cold and wet. I used to get it on my old S-type from time to time.

With the coming of the Summer, matters improve. A recent front bumper cover off, allowed me to pull the connectors off the backs of the sensors and have a bit of a dry out and clean up session. The socket pins were then given a smear of electrolytic grease. The sensors regained normality. I was lucky as no new sensors were needed.

I still have to tackle the rear bumper cover an do the same maintenance. That end of the car gives the worst problems.

If you put the car in forward or reverse, dependent on whether you just have reverse sensors or both front and rear, with the ignition switched to the first position, you should be able to go to each sensor in turn and listen for its clicking sound when working. One or more that do not click are almost certain to be the ones that are causing the issue. My iCarsoft 930i scanner can also read the offending sensors and even goes as far as telling you which one is defective.

Ice, frost, water and pressure washing can cause issues. Doug also mentions an excess of paint. If needing a new sensor, only the very minimum of thin spray paint coats should be applied. Most would agree that if a sensor is faulty and needs replacement, only genuine Jaguar OE units should be fitted. After-market sensors have been known to cause further issues.

Most time in rectification is spent removing the bumper covers so expect to spend a morning removing the various nicely buried fixings to get the cover away from the car. I believe that on an S-type two of the rear sensors are accessible by removing the rear light clusters. Make sure you reseal the clusters well after removal. They can be notorious leakers!

Mike K