[chittychittybangbang]

This is a follow up on a post at audiworld:

Cliffs: the dealer forgot to top off a Q7 TDI adblue tank and the low level light came on. Dealer showed him a TSB that said only the dealer can get the adblue tank to know it has been filled up. The real problem is that if the adblue tank thinks it's empty it will cause a no start condition due to not meeting emissions. (Technically I think it'll let you do 1 start after the final warning).

The post and the follow up posts:

Got a Q7 TDI, and at the 5k service the dealership didn't fill it up with AdBlue. Result was that
around 11k miles it gave the warning of 1500 miles left. Called to see if I could just buy
the AdBlue and fill it myself. (had to speak to 3 different people before I got someone who knew what that was)

The dealership ended up filling it, but in the process they gave me a "Technical Service Bulletin" which seems to address a problem of the "Refill AdBlue" message show despite adequate level.

The solution is to use a diagnostic computer to run a function called "Adapting reducing agent tank adaption values". The bulletin indicates that this is normal procedure when re-filling with AdBlue!?

So does this mean that one really can't re-fill AdBlue at home? I understand that physically I can add it, but if the sensor has to be reset, it does me now good as the engine will not restart once it runs out.

Hi ChrisR,

I expect that the user friendliness of AdBlue (in the USA DEF - Diesel Exhaust Fluid) will be a major subject of discussion in the future.

I am the Managing Director of an AdBlue refuelling equipment supplier to the auto and truck industry. One of the major early complaints with AdBlue will be the ease of refuelling by trucks, compared to passenger car owners. This is a difficult question to answer, but is based on the comparative sizes of tanks and the refuelling flow rates in the two vehicles.

It will not be for the forseeable future be possible to refuell AdBlue in the same way that you can refuell gas in your car. We are working together with Audi on possible solutions, but the amount that each vechile needs is small in comparasion to diesel or gasoline cars and that because of the aggressive chemical nature of AdBlue regular pumps are not economically feasable right now.

Your problem relates to a simple safety mechanism. Audi has given assurances that this technology will perfom as designed for the vehicle's lifetime. Without proper safeguards, it would be possible to pour tap water in the tank and nobody would be the wiser. Naturally the exhaust emmissions would be enormous and the vehicle's AdBlue onboard system would be destroyed. The legislators as well as the car manufacturers would prefer this not to happen, therefore controls have been put in place for unscrupulous drivers.

The environmental and economical benefits far outweigh any negatives and buyers of cars fitted out for AdBlue should not be discouraged from purchasing this technology.

I hope that you have great pleasure in your Q7 and can assure you that you have made a wise choice.

More :
For the moment, the preferred method of DIY refueling refueling is with a bottle. You can see more at http://www.youtube.com/watch?v=ezUPuUHGa04

With this method, as you can imagine such a sensor is not necessary. However, there is a sensor on board that will detect that another (different from AdBlue) liquid has been put into the tank. If refueling with an incorrect liquid is performed and the senor detects it, the vehicle will either not be able to start or will have restricted power (depending on manufacturer).

Full refueling of the AdBlue tank is for the moment only practical at the dealership. This is something that all manufacturers want to change. It is simply not acceptable that cars are being developed with increasingly longer service intervals and that customers must return to the dealership for a refill. Also, the overheads (and mechanics hourly rates) at a modern dealership mean that they must charge a high price for the AdBlue. The strategy for the manufacturer to increase sales of SCR vehicles means that they want the price of AdBlue to remain relatively cheap, compared to the diesel price.

In the future, when the number of cars requiring AdBlue increases, all car manufacturers would prefer that their customers refuel at a regular gas station.

When the new European emission legislation kicks in, all diesel powered cars will need to have SCR. It is simply not financially viable for Audi (and all other car manufacturers) to have two separate engine development programs. Whether or not the Audi A4 TDI is available with SCR, is a question that you need to address to your dealership.

 

[Bobbyk]

I'm confused, the TSB says you can't fill it up but the video shows how to fill it up?

 

[chittychittybangbang]

The TSB is for Audi. The video is from a Benz.

What the adblue manufacturer is saying is that different companies have different solutions to solving how to fill adblue. Benz says you can fill it up yourself. Audi says you can but the sensor doesn't know that its been filled up because you could also put in other stuff. It would destroy the adblue system if you did, and I guess Audi doesn't trust their owners. This is my interpretation of what the original post says.

I haven't gotten the TSB but the original post says that it's normal procedure to use the computer to tell it that the adblue has been topped off. I suspect that VCDS could also do something similar but you shouldn't have to use VCDS to do something that it should know. This is unacceptable as the adblue maker says, because of the cost and inconvenience of dealer service. And if you're low on adblue far from a dealer you're screwed even if you do have adblue.

 

[bigshow]

What a rip off.

I suspect that you are right. It's the same way with the service required lights on some BMW. The dealer has to reset it. I think that there are some obd2 scanners or tools to reset it too but the VCDS should be able to do it too. The difference is that the car will still start....

 

[Teefer]

That sucks. The dealer must love it though since it keeps you coming back. VW/Audi better follow Benz or else they will have a lot of unhappy customers.

 

[Fluid]

This is interesting:

Audi has given assurances that this technology will perfom as designed for the vehicle's lifetime. Without proper safeguards, it would be possible to pour tap water in the tank and nobody would be the wiser. Naturally the exhaust emmissions would be enormous and the vehicle's AdBlue onboard system would be destroyed.

If you damaged the adblue system by pouring water in there wouldn't the engine not start? Or at least trip some major codes?

There's that "lifetime" term again....150,000 miles and then it has to be overhauled?

 

[chittychittybangbang]

I guess what he's saying is that you could dilute the adblue but of course, it cause damage to the system. Adblue has some water in it already but I imagine that too much water would cause damage. I'm surprised someone's Q7 already has 11k. I've heard some reports of TDIs getting 100,000 miles on them /year though so I guess he wanted better seats or something.