PlasticMac
Admin Team
Leaving side lights on before disconnecting the battery has the same effect.
Mac.
retro fit steering wheel
- Thread starter pc759
- Start date
Mac.
2work
Well Known Member
Evening Arthuar,
I withheld posting here to see if anyone else wished to jump in to assist but also notice you’ve already had some very good pointers from others already, as you’d expect from the community spirited membership of this fine Club.
As Steve @A2Steve said, best obtaining a steering wheel that comes with the correct loom. This of course won’t help right now but definitely sound advice for future reference. Others reading this take note of Steve’s advice as it will save a headache in the future.
Additionally Graham @audifan has yet again hit the nail on the head: In your particular situation the very best course of action is to locate the correct loom for your updated arrangement. Dave @Special edition has also added that the loom could be available from Audi. That said, there are alternative options available to you as the 8Z0 3 spoke sports steering wheel was fitted into a few models of the same era that has the loom you require. This item here could be of interest to you.
Adapting a SE loom to a Sport loom has been mentioned before and will add the link if I can find it. As you have already got the airbag connected (asssume this is the case from your post) then there is no need to touch these wires and I suggest you don’t.
Point to note which have been previously mentioned early on in this thread: Airbags are designed to save life by reducing body part impact etcetera, if their wiring is adjusted by unaware DIYers then they can potentially take life or certainty cause life changing injury. Please do as much research as possible regards removing airbag connectors along with static build up and power source removal. I’ve been vague here for a reason as you should only proceed once you’re fully aware of the risks involved and feel confident to do so. There is absolutely nothing wrong with admitting defeat and seeking professional assistance on matters like this.
Understanding that you only need to adjust the horn connections then avoid the 2 airbag wires from the yellow slip ring connector to the connector in the very centre of the airbag. You need to concentrate on the 2 wires that leave the yellow slip ring connector and go to small white connector (might also be black so adding a picture will help) to the side, these are the horn wires.
Back to the 2 horn wires in the white (or black) connector:
White
Black
Not in pinout order: One is connected to the battery negative terminal via the vehicles earthing points and of course the slip ring. The other wire is only routed to the horns negative supply, again via the slip ring. When you press on the airbag to activate the horn then both these wires make contact to complete the circuit and produce the audible tone requested.
Using this link should provide you with an idea of what is involved to adjust the horn wires, which should really be done by a professional.
If none of the above is crystal clear then please seek professional assistance form a qualified auto electrician who has access to the necessary wiring diagrams.
One final option, if you continue to struggle to resolve this is to send the loom to someone in the UK who has experience in this area. It would mean your vehicle in unable to be used whilst the loom was away on its travels but once with an experienced person then it be back in the mail system within hours of receipt. The alteration procedure should be very quick. Shipping will be the expensive part here so please do investigate the other options that are available to you, it’ll no doubt be cheaper to simply purchase the correct loom for your new steering wheel.
Kind regards,
Tom
audifan
A2OC Donor
Although fully echo Toms words I still think obtaining the correct loom is the best plan. Air bags need to go off when required and not go off at any other time. I for one would be VERY reluctant to give "instructions" as to how to rewire the air bag or horn wiring for this very reason. If the instructions were not followed the person giving the instructions could be held liable for any injuries. I know this is a bit of an extreme comparison but we all remember how blame was passed in a certain Formula one incident in Italy where a driver unfortunately lost his life over a steering component issue.
Yes we want to help but good intentions can go badly wrong with severe consequences so please do not temp members to give you this information. Regardless of this caution someone inevitably will
Yes we want to help but good intentions can go badly wrong with severe consequences so please do not temp members to give you this information. Regardless of this caution someone inevitably will
Rickmeister
A2OC Supporter
I understood that they came with a punch mark as new which lines up with one on the steering column to help it locate in the straight ahead position on the splines...
Anyone confirm?
PlasticMac
Admin Team
Yes they do, it's a line, like a tap with a small chisel.
I took a pic of mine before removing it, as the spline pitch is very fine. Compared the pic when refitting.
Mac.
timmus
A2OC Donor
Just to clear up the confusion here...
Yes, there is a line that indicates the centre-point of the steering column. Similarly, there is a line on the steering wheel that allows you to fit the steering wheel onto the steering column such that everything is nicely centred.
According to Audi, a punch mark should be left on the head of the M12 XZN bolt that fastens the steering wheel to the steering column, such that anyone can easily see how many times the M12 XZN bolt has been removed and retightened. There is no suggestion that the steering column or steering wheel need to be punched or marked in any way.
As discussed via private message, I'm happy to resolve this issue in person when I'm in northern Italy later this year. Hopefully we'll be able to meet.
All the best,
Tom
Richard 13B
Member
Afternoon everyone. I know this thread is a couple of weeks old, but there is some worrying stuff going on here which as an automotive safety specialist with many years of airbag experience, including safely deploying many thousands of VAG airbags, I can't let this go without flagging some warnings!
1) If you change a steering wheel, always try and re-use the original airbag. Airbags are NOT all the same. They have different inflation volumes, vent sizes, fold patterns and power levels. The one developed for the A2 will take into account the effects of the geometry of the A2 occupant space and the characteristics of the other driver crash loading points - notably the seatbelt (the webbing stiffness), the load limiter setting (the diameter of the torsion bar in the retractor), the seat pan stiffness, the knee bolster distance and stiffness and the steering column collapse load level and ride-down characteristic. These are all tuned with each other to give the optimum protection to a range of occupants in the A2. I don't think the A2 restraint systems changed over its short production life - but a check on airbag part numbers and seatbelt retractor part numbers would confirm this. Restraint system facelifts would mean you have to replace airbags and belts from the same year. If you use any old airbag from a different car, it probably will not protect you as well in a crash - in extreme cases, it might even be worse than no airbag at all. My real worry here is that many want to use the TT steering wheel. The driver posture in a TT, and hence the occupant load distribution paths are TOTALLY different to those of the A2. As a general rule, sports car airbags are much smaller in inflation volume than saloon cars, as more occupant load goes into the seat pan.
2) Be careful when handing and storing airbags. ALWAYS, store or rest them FACE UP. Never put them face down on a hard surface. If something does cause them to deploy when face down, they will become a missile which can kill you. I used to do safety demos with driver airbags face down (deploying from a safe distance) but don't anymore - lost too many airbags and connection cables when they ended up on people's roofs! If it deploys face up, it might jump a couple of feet - but it won't kill you. Either way, the bang might well cause you to need an underpants change!
3) Shorting links are there to prevent static build-up on the airbag terminals. They link one terminal to the other. In each connection along the route from the ECU to the airbag (or pretensioner), every downstream side of the connector will have a shorting link. When the connection is made, a plastic tang in the mating connector will lift the shorting link away from one or both terminals. So in Tom's photos, there will be a shorting link in the squib housing in the airbag casing itself, there will be one in the yellow connector on the short harness, where it plugs into the clock-spring. There will be another on the far clockspring connector too. If everything is fine, no problem. But if any harness becomes damaged, or you suspect it could be, then always remove the last connector which goes into the airbag itself, and check the wiring carefully at leisure. On the photo above, pushing the yellow locking clip into the purple connector will lift off the shorting link in the airbag side of the connector.
Over the years, I have handled and recycled many airbags - including ones with faults. The good news is that of the VAG range, from my experience, A2 airbag problems were extremely rare. (Don't get me started on Golf Mk5 driver airbags!)
Always happy to talk VAG pyrotechnics with anyone who wants help or advice.
Best regards,
Richard
1) If you change a steering wheel, always try and re-use the original airbag. Airbags are NOT all the same. They have different inflation volumes, vent sizes, fold patterns and power levels. The one developed for the A2 will take into account the effects of the geometry of the A2 occupant space and the characteristics of the other driver crash loading points - notably the seatbelt (the webbing stiffness), the load limiter setting (the diameter of the torsion bar in the retractor), the seat pan stiffness, the knee bolster distance and stiffness and the steering column collapse load level and ride-down characteristic. These are all tuned with each other to give the optimum protection to a range of occupants in the A2. I don't think the A2 restraint systems changed over its short production life - but a check on airbag part numbers and seatbelt retractor part numbers would confirm this. Restraint system facelifts would mean you have to replace airbags and belts from the same year. If you use any old airbag from a different car, it probably will not protect you as well in a crash - in extreme cases, it might even be worse than no airbag at all. My real worry here is that many want to use the TT steering wheel. The driver posture in a TT, and hence the occupant load distribution paths are TOTALLY different to those of the A2. As a general rule, sports car airbags are much smaller in inflation volume than saloon cars, as more occupant load goes into the seat pan.
2) Be careful when handing and storing airbags. ALWAYS, store or rest them FACE UP. Never put them face down on a hard surface. If something does cause them to deploy when face down, they will become a missile which can kill you. I used to do safety demos with driver airbags face down (deploying from a safe distance) but don't anymore - lost too many airbags and connection cables when they ended up on people's roofs! If it deploys face up, it might jump a couple of feet - but it won't kill you. Either way, the bang might well cause you to need an underpants change!
3) Shorting links are there to prevent static build-up on the airbag terminals. They link one terminal to the other. In each connection along the route from the ECU to the airbag (or pretensioner), every downstream side of the connector will have a shorting link. When the connection is made, a plastic tang in the mating connector will lift the shorting link away from one or both terminals. So in Tom's photos, there will be a shorting link in the squib housing in the airbag casing itself, there will be one in the yellow connector on the short harness, where it plugs into the clock-spring. There will be another on the far clockspring connector too. If everything is fine, no problem. But if any harness becomes damaged, or you suspect it could be, then always remove the last connector which goes into the airbag itself, and check the wiring carefully at leisure. On the photo above, pushing the yellow locking clip into the purple connector will lift off the shorting link in the airbag side of the connector.
Over the years, I have handled and recycled many airbags - including ones with faults. The good news is that of the VAG range, from my experience, A2 airbag problems were extremely rare. (Don't get me started on Golf Mk5 driver airbags!)
Always happy to talk VAG pyrotechnics with anyone who wants help or advice.
Best regards,
Richard
Thank you for this great input in the airbag ''story''.
It was very eye opening and full of new info, especially regarding limited compatibility of airbags between different cars.
Just one question: are many airbags shared between different cars? So not only by the shape and that you can use them in different car because it is a click on retrofit, but that the airbag has exactly the same part nr.?
It was very eye opening and full of new info, especially regarding limited compatibility of airbags between different cars.
Just one question: are many airbags shared between different cars? So not only by the shape and that you can use them in different car because it is a click on retrofit, but that the airbag has exactly the same part nr.?
Richard 13B
Member
Hi @mtl . Yes. The only way to be sure that any different airbag is a safe swap, is to have the same part number. Sometimes the part number will be different only because of the colour, but you need to understand exactly how the part number is made up to determine if the airbag is functionally the same. Even then, if it is an elderly sodium azide based propellent, I would advise against it. (Don't worry - yours isn't!) As you say, the module might fit in the steering wheel, but the airbag itself might not be suitable.
Years ago, I was responsible for the integration on the restraints on Rover 25 and 45. The modules were a "steering wheel fit" compatible with the previous Rover 200 and 400, but the airbags were larger (nominally 45 litres up from 30). In crashes, these gave better rim coverage for head impacts, but we had to introduce load limiters on the seatbelts to keep the chest loadings down. All the restraint parts were a straight swap for fit, but only worked properly together as a set - you couldn't mix and match.
As an aside, airbags usually have a limited life printed on them. Typically for this era, it was 10 or sometimes 15 years. In the early days of airbags, the propellant was sodium azide. It was stored in pellet form in a foil bag inside the inflator. When the squib is initiated, it gets hot and the azide reacts. The speed of reaction is important. Too slow and the bag never gets into the correct inflation shape, or not at the right time. Too fast and the bag can over-pressure and split during the unfolding phase - neither is good. The thing that affects speed of reaction is the surface area to volume ratio of the pellets. Being shaken about in a car eventually causes them to crumble, causing a greater surface area to volume ratio: too fast. They may even to settle down away from the squib in extreme cases, so the bag doesn't inflate at all!
By the time of the A2, the pyrotechnic materials were mechanically more stable. Some are still badged as having a 10 year life, but in my experience, they work fine well beyond this as long as they remain sealed. In my opinion, harsh vibrations (sports suspensions, dodgy roads) and high mileages are more of an issue than age. If my A2 had over 200k miles on it, I would be considering changing the pyros for some from a lower mileage equivalent. As mine has only 80k on it, I am not worried.... even though the airbags are "out of date" by about 9 years! I would never put in an airbag if I didn't know it had a low mileage history, of course!
I hope these ramblings are of some interest to someone!
Years ago, I was responsible for the integration on the restraints on Rover 25 and 45. The modules were a "steering wheel fit" compatible with the previous Rover 200 and 400, but the airbags were larger (nominally 45 litres up from 30). In crashes, these gave better rim coverage for head impacts, but we had to introduce load limiters on the seatbelts to keep the chest loadings down. All the restraint parts were a straight swap for fit, but only worked properly together as a set - you couldn't mix and match.
As an aside, airbags usually have a limited life printed on them. Typically for this era, it was 10 or sometimes 15 years. In the early days of airbags, the propellant was sodium azide. It was stored in pellet form in a foil bag inside the inflator. When the squib is initiated, it gets hot and the azide reacts. The speed of reaction is important. Too slow and the bag never gets into the correct inflation shape, or not at the right time. Too fast and the bag can over-pressure and split during the unfolding phase - neither is good. The thing that affects speed of reaction is the surface area to volume ratio of the pellets. Being shaken about in a car eventually causes them to crumble, causing a greater surface area to volume ratio: too fast. They may even to settle down away from the squib in extreme cases, so the bag doesn't inflate at all!
By the time of the A2, the pyrotechnic materials were mechanically more stable. Some are still badged as having a 10 year life, but in my experience, they work fine well beyond this as long as they remain sealed. In my opinion, harsh vibrations (sports suspensions, dodgy roads) and high mileages are more of an issue than age. If my A2 had over 200k miles on it, I would be considering changing the pyros for some from a lower mileage equivalent. As mine has only 80k on it, I am not worried.... even though the airbags are "out of date" by about 9 years! I would never put in an airbag if I didn't know it had a low mileage history, of course!
I hope these ramblings are of some interest to someone!