I started getting the 3 second beep when I hit reverse, indicating there is a fault with one of the sensors. Scanned the car and found the front left sensor intermittently working.

 

Not an urgent problem BUT, the rest of the sensors don't beep anymore when I get closer to stuff.... Is this right? I mean, after the 3 seconds beep I would expect to have the other 7 sensors still beeping to indicate the distance... :(

With only rear parking sensors, in my experience, if one sensor goes bad enough to trigger the 3 second tone, the system is completely inoperative.

 

Having just replaced another 2 sensors, problem was intermittent constant tone without obstruction, I have found an easy way to find the bad sensor(s).

 

1. Switch on ignition.

2. Select reverse gear.

3. Open boot, you can now view display and hear tone from the rear of vehicle.

4. Listen closely to each sensor for a clicking sound. A silent sensor is inop and faulty ones giving a proximity warning can be silenced by completely covering them with a finger tip. If your hearing isn't up to detecting the ultrasonic clicks a light finger tip can often feel them.

 

Make sure the sensors and surround are clean before testing as dirt can affect their operation.

Got both back and front sensors. I plugged in vcds and know which one is faulty (front left one) - I also checked for the clicking and confirmed.

 

I find it strange that the system is inoperable with only one faulty sensor.... I would expect it still worked just without the faulty one.

True, however how would you have it display failure...

 

'Please use caution when parking-front left sensor inop!'

 

A £10 DIY job to fix proximity warning system.

Yeps - I will be on it within the next 1-2 weeks. 

 

Will try to take pics for future reference.