Rear Parking Sensors

[Ronlynne]

Hi can anybody help with the parking sensor service i.e. What is it and how do you do it

 

Ron

[blackvelvet]

when you shift into reverse gear. the sensors in the rear bumper 2 each side, cause lights to appear in the rear of the ca,r if you are within 6 ft of an obstacle. At 6 feet the light should show yellow, as you get nearer to the obstacle the yellow lights increase in number,. when the yellow lights go out and red light shows on it's own, that is as close as you want to get.

[bignev]

Mine is very slightly different - the closer you get the more yellow lights, then IN ADDITION the red lights (up to 2) come on as well and the beeper sounds solid, and the radio volume goes off at this point too.

 

But of course you actually asked what is the parking sensor service. Not how they work. No idea what that is sorry!!!!

[QinteQ]

Electromagnetic or ultrasonic, I'm not sure which, I think the sonic is the internal one because it reads any interrupt whereas magnetic can read distance.

[Ronlynne]

Thanks

but Get with the programme what I asked is what is the "Service Park Assist "what is it and how do you do i

 

 

Best Ron

[soupstone]

You have a fault with the reversing sensor system, or "Park Assist" 
Just went out to confirm, I had the same warning, as the in car display had been knocked off. I've just reattached it and the warnings gone. 
So you just need to find out whats broke, and fix it. 
 

[Ronlynne]

Hi

 

Thanks for the advice

if I could find what's wrong I would fix it, that being the case I wouldn't be on the forum asking for help would I

[soupstone]

I'd start by giving all the sensors a good wash and inspect for damage.

 

 I've read in the past the sensors give off a humming sound or you can feel a slight vibration from them.
Get someone to sit inside, with the handbrake on and the foot brake held firmly, and get them to put it into reverse. Listen to, then touch each sensor, and see if any one is different from the rest. 

If that's not conclusive, time to go underneath and inspect the wiring/connections, and, if you have a multimeter, perhaps test the sensors. I'm not sure how accessible they are though. 

I'd think Youtube will have a video on testing them, just do a search for "reverse sensor testing", the method will likely be the same.

[Ronlynne]

Hi

Thanks for the advice that was my next task I'll keep everyone posted at least if it cures the problem it'll help somebody else

 

Regards Ron

[andyb2000]

Hi Ron,

 

Also please specify what year, model, variation, etc, and you'll get more replies with more specific information. I've found several different parking systems on the MK-IV editions, but they all work on a similar principle, each sensor is two-wires that link back to a control box, normally in the rear passenger side in the boot (Difficult to get at, on mine it's between the join between rear section and speaker for rear passengers), but all wires will go back to there generally.

 

You can test an ultrasonic sensor in a very rudimentary way by using a multimeter like soupstone says, you need to be on the ohm reading and it'll measure something like several thousand ohms, compare each of them and you should hopefully see one with a vastly different resistance (or infinite).

 

Good luck and hopefully you can locate the wiring harness they lead back to with a connector for easy probing/testing.

[Ronlynne]

Hi Andy

At last someone who understands the problem the vehicle is mk4 Feb 2008 2.8 diesel auto I've just bought some electrical contact cleaner so I'll start with the sensors and go from there I also have a 7 series beemer with the same problem on the beemer you can hear the sensors clicking when the car is in reverse so it's easier to detect which sensor is defective

 

Best Ron

[mikebh8]

Hi, does the reverse light/lights at the rear of the car come on?

The reverse lights and the sensors are linked through the same switch, on the gear box(mine 2004 is on the left hand side of the car behind the wheel), otherwise the sensors won't know that the gear is switched to reverse.

Hope it helps.

[Jodel]

I need to replace some of the parking sensors on my 2007 2.8 CRD. Looking on the internet at several parts suppliers, there seem to be a number of different makes, with the right angle connector and different lengths of body. Do they all fit, or do I need to dismantle the bumper to check the type?