Reversing sensors unreliable

[hsyben]

2003 E85 Z4 2.5i
I've had this car for a year now and love it to bits - even beats the first gen MR2 I owned 30 years ago. However, although the parking sensors worked fine until recently, they have started to beep briefly as soon as I put it in reverse and then beep intermittently when I am not that close to an obstacle. This makes them unreliable and not very helpful. Is there a way to re-calibrate them? Or is there a control module that might need replacing? Or have they become like me - old and quixotic!

 

[j3nks79]

Give them a blast out with wd40

 

[hsyben]

Thanks.
Interesting? From the front or the back?

 

[j3nks79]

Front the front. Get all the dirt and moisture out.

 

[parabolica]

If that doesn’t work, one or more of the sensors may be broken - put your ear to them whilst the car is in reverse to see if you hear a clicking noise - no click = broken sensor. You can replace them easily.

If, like me, the sensors seem fine then it might be the pdc control module found in the boot; you could try replacing that as a last resort.

 

[hsyben]

Thanks, I'll try that. Why do they click? Dolphin impression?

 

[dmo]

put your ear to them whilst the car is in reverse to see if you hear a clicking noise - no click = broken sensor. You can replace them easily.

Pls make sure your handbrake is on and firmly on and check a third time when you jump out the car before you stick your head behind your car whilst its in gear. :?

 

[hsyben]

Now you tell me!

 

[NaweedMustafa]

Thanks, I'll try that. Why do they click? Dolphin impression?

Thats the nature of these ultrasonice sensors, something to do with a diaphram that vibrates when electricity is applied, then teh sound waves are emitted, if it bounces off an object, it reflects back. Through magic, it determines if theres an object.

as mentioned before, blast the sensor with WD 40. otherwise, do an audible check on each sensor

 

[hsyben]

Thanks. I'll give it a go.