I have seen that A2 can has a difference seat belt fastening on the seats that has a wire for the warning. After checking wiring diagram I have seen that this fastener with cable should the connected to the dash panel. So I suppose that if I install and connect this type of seat belt fastner I might have a sound warning as the dash panel recognize that seat belt is not fasten. Did anyone ever tried this ?
The spare codes for this seat belt fastener is 8Z0 857 755G.
Evening,
This is a reasoned question as it does look like there is possible provision for the A2 instrument cluster to give you an audible seatbelt warning, although putting your seatbelt on should be a 'business as usual' occurrence before pulling away in any vehicle. That said I feel you should have something in return to your query. My answer here is purely an assumption with no hard evidence to back it up. It's an interesting venture though which I hope you undertake and report back on.
Here's the
seat belt buckle you mention with a 8Z0 part number:
It looks to be a 2 wire operation where one wire might be grounded and the other go to the instrument cluster as you mention (similar simple circuit like the brake pad wear sensor or washer bottle level sensor). When the seat belt key/blade part is inserted into the buckle it creates or disrupts the circuit with the instrument cluster pin being either grounded or not. The red connector looks like it would fit within the connector carrier under the seat where there is room for 3 connectors. I have 2 sets of heated and electric lumber seats which only occupy 2 out of the possible 3 spaces on the carrier, maybe the third opening was going to be filled by the red connector you see in the above picture, certainly looks to be the same shape/size. The airbag connector is attached onto the side of the carrier and certainly doesn't occupy this third aperture.
The real unknown is will the instrument cluster beep/gong if there is no seat belt inserted into the buckle once connected up, thats if my above theory on the wiring is actually correct.
You can certainly code the instrument cluster to give a seatbelt warning which just displays the seatbelt icon for 3-5 seconds when the ignition is first switched on. I've already coded one of my clusters to do this whilst I was playing with settings for another venture I'm yet to release my findings on.
You have no doubt come across the same information as I'm about to show but for everyone else's benefit, here is where the seatbelt buckle might be fed into the instrument cluster:
Green Connector
Pin 27 is named as Belt Buckle.
I cannot confirm if any of my fleet has anything attached at pin 27 but if it does I can only guess that it's already grounded out within the harness.
To test this theory I think that you would need to code your cluster to provide the seatbelt warning and also have pin 27 connected to an earth. If it beeps then the theory is correct and it should be a straight forward retrofit to enable this feature that never made it to the production line.
As the wired buckle costs EUR 62.51 before any shipping fees from Audi Tradition I personally wouldn't be looking to give this a go anytime soon but maybe something for the back burner if I ever run out of things to retrofit. I guess that a similar buckle might be found in a breakers yard for pennies but very much doubt it'll sport an 8Z0 part number.
The question of whether or not it is needed or necessary is entirely up to the person wishing to give it a go. I can fully appreciate someone wishing to finish off something Audi started and for whatever reason never rolled out, even if it doesn't give any further functionality apart from being annoying if you fail to abide by the law and choose not to wear a seat belt. In all honesty, most people try to stop the warning beep, not add to the list of things that can trigger it.
As my cluster is already coded for belt warning I'm wiling to test my theory by removing pin 27 (if there is a connection that is) but it'll be a while before I next have the instrument cluster removed. I do have a cluster bench test setup but this wouldn't help as I have multiple warning beeps due to it looking for the circuits that I don't have connected so would be a waste of time.
If you're familiar with removing the instrument cluster and have VCDS then my above guess work can be quickly tested. If there is nothing in pin 27 then all what I've just typed is completely incorrect and I'd draw to the conclusion that this retrofit may result in nothing.
I’m also unable to find any evidence of anyone else giving this a go, perhaps you will be the first as you have already done your homework on this.
Kind regards,
Tom