Reversing Sensors

^adam^

^adam^

Active Member
VCDS Map User
Joined
Jun 3, 2015
Messages
261
Reaction score
41
Points
28
Hi all,

S4 Avant 2004

My new Avant has reversing sensors, but I don't think they're working correctly. I think they are OEM.

When I start the car and put into reverse, I hear a long beep, about 5 seconds. Drive around as normal, but when I go to reverse I hear no beeps when getting close to something.

If I don't switch off the engine, drive around again, then stick in in reverse again, I hear no beep at all.

I think it's intermittent, as I'm pretty sure they were working OK when I looked at the car.

Also, had a quick read around the forum (which is great BTW!) and I saw something about a control unit in the back left of the boot. I opened the cubby hole but it was empty?

TIA.
 
Will be a dead sensor. If you have VCDS then give it a scan. If not put the car into reverse with the ignition on and run your finger close to each sensor, your feel a electronic pulse feeling, the one that isnt pulsing will be the faulty one:chuncky:
 
Excellent, thanks, one sensor throws off the whole set?

Interesting. I'm guessing a single sensor can be ordered from Audi direct?
 
Yup, my wife's a3 has one faulty sensor and stops the whole lot working. I clear the code on it and it sometimes starts working again but then stops working quite soon after. Yeah should be able to order from Audi or check on ebay
 
Excellent thanks, will check tonight. Much appreciated.
 
So the touch test highlighted that the centre of the three sensors isn't working.

Time to find part numbers for a replacement!
 
Mines the same as yours, has been since I bought the car.
I get the short beep followed by a long beep (which indicates an error)
I've not tried the 'touch' test, I've been looking an idiot on my drive with my ear to each sensor listening for clicking, which is also a way of finding out.
Mine were all clicking at one point, last time I tried it there was one silent.
I've had it scanned when I had the cambelt changed & it was found to have 1 duff sensor & 1 had a different error code, which the mechanic said it could be the wiring?..

many months on & I've yet to try it, I found they sell OEM ones on ebay for just over £20 so been meaning to get one. (or do I get 2??..)
Let us know how you get on? are you planning to change them yourself? I need to get the balls to remove the rear bumper, but not overly sure how to go about it..

One day
 
Yeah I'll be giving it a go for sure!

Getting a VCDS scan on Sunday by @Ash187 and that's one of the issues I hope to diagnose.

Then I'll be ordering a couple of replacements. I wonder how much they are OEM from Audi v OEM eBay?
 
I was told the cost from a mechanic who scanned it but can't remember the price, i'm pretty sure it was around the £70 mark (don't quote me on that though)
Then obviously needs painting.

Any chance you could take a few photos when removing the bumper?
I've not found much of a write up to removing it. From what I've seen it looks doable to my untrained hands...
 
It might be cheaper to buy a new kit.
cobra i think.
means reinstalling new sensors alot of fiddling.maybe cheaper just a suggestion.
 
Audi are £106 inc vat.

I managed to get a boxed Audi un-used from eBay for £40 inc postage.

I'd be surprised if those linked above are true OEM for that price?
 
as the old saying goes.. if it looks too good to be true....

I'm tempted to send a message to the seller & ask the question to see what the reply is.
it's a massive price difference thought, so not holding much hope.
 
I fitted OEM type but Cobra branded to my Cab, takes a while but worth it. Loads on ebay. Just make sure you drill exactly the right sized hole, even a mm too big and they wont fix firm. If its a cab you will need the headrest guides.
 
Well I've had a reply about the cheap sensors..


The sensor appears exactly like the picture. It has the Audi logo and is genuine.

The numbers of the part: 4B0 919 275 B
 
Guess I paid too much for mine then!
 
Judging by the Audi price you did alright.
Plus yours is definetly genuine, these sound OK so might get 2, I did the touch test and 2 don't seem to be working!

Do yours look like the eBay one I posted?

Also is there a knack to pulling the bumper off the body work?..
Any hints n tips would be appreciated as I'm going to give it a go.

Have you sorted yours out now? I guess you can just use a rattle can to do a few coats of paint on them?
 
Yup looks the same as the one you posted.

Bumper off is tough. Remove lights, remove interior boot side trim, remove trim around boot latch, I had to also remove the complete Bose system.

Then there's 5 nuts per side that need to be removed, three further down and around light height. Then prize the bumper away from the rear quarter panels then pull away. The cables won't let the bumper drop to floor so be careful
 
Thanks for the run down on that.
It's the prizing the bumper away from the body panel that i'm most afraid of!!...
From looking, theres a couple of screws in the rear arch screwing the bottom of the bumper on too, I guess that's additional to the 5 nuts per side then.

It's nice to know you've successfully removed without damage... you wait for my next thread asking the cost to have a bumper & side panels filled sprayed & fitted lol!!! that's about how my luck goes.

Is the bumper just clipped into the rear quarter then? so literally just carefully pulls out? I guess it all becomes clear when the thing is off lol
 
Yup, forgot to say, there's a couple of screws in the wheel arches that hold the arch trim to the bumper. Two per side I think.

Rear bumper clipped into rear quarter.Pull it outwards around the quarter before pulling bumper away from rear of car.

I think I'm going to need to get both bumpers resprayed also :(
 
Please tell me yours needed spraying before... and not as a result of removing it!!...
My back bumper is fine at the moment, the front is showing it's age unfortunately. 130k & 11years worth of stone chips!...
 
Yes, a few marks on it before.,

Find an old bit of carpet to lay down just in case ;-)
 
How's the sensor fitting going? I've just hinted to my old man that I might have a little job for us to do shortly lol!!

Did you notice if all the sensors are exactly the same? I assume they are but the ones I found on ebay (which I linked earlier) I've noticed the same selling is doing some that look the same for £15.75 each??? I've asked them the difference as it seems odd..

How do the sensors grip the bumper? do they push in & then clip or is it like a key holding them? I'm just wondering as I might be able to reach one of them from underneath, but having no idea how they are held in makes it impossible to remove.

Cheers
 
Yeah all done.

The bumper off is a bit scary to be honest. But it's just a case of working through all the steps in order. The video posted above is a little bit of a help.

The sensors are clipped in and all the same from what I gather. I'm glad I got a proper Audi one as it's not a job I'd like to tackle again if the aftermarket part doesn't work.

The sensors are clipped in, you have to pull the clips outwards then can push the sensor out the back of the bumper. On refitting, you have to ensure the sensor is a. the right way up, and b. at the right angle in terms of rotation as there are guide holes to locate the sensor properly.
 
nice one cheers,
sorry for all the questions!... just trying to get as much info on it before delving in. (if I ever find a day free to have a bash!)
Did you get any photos of the bumper off that you could post at all?

I take it you just bought rattle cans & blew a bit of paint over them.. not really found any info on painting them, didn't know if you needed to put anything in the inner gap to keep paint out? or is it a simple case of a few thin coats of colour & some lacquer?
 
I didn't get any pictures unfortunately as it was getting late :(

Painting wise, just picked up a can of colour and lacquer from Audi. I got a piece of newspaper and poked the sensor through as to get no paint on the rear of the unit.
 
is there a protection ring that slots in for painting then?? I thought I read somewhere about that?
also, do you need primer, colour & lacquer? or are they ready primed.. don't want to add anymore layers than needed in case it has any adverse effects.
 
Out the box, painted, installed.

No idea about any protection ring, Seems to work OK.

Didn't bother with primer.
 
You must log in or register to reply here.

Similar threads

I
Reversing sensors.
Replies
13
Views
1K
YSN
YSN
V
B6 Cab reversing sensors
Replies
5
Views
757
VagCabby
VagCabby
lt barnett
reversing sensors A4 Cab
Replies
0
Views
851
lt barnett
lt barnett
G
A4 TDi Sport 2002 reversing sensors
Replies
0
Views
682
greg1953
G
medicpaul
Fitting reversing Sensors to an AVANT
Replies
13
Views
3K
Cabbyfan
C
Top
Back