A8 2.8QS '52 plate engine management light

Titan · #1 28th February 2011, 11:41 AM

First time poster fron new owner so go easy please!

I have an engine manegement light on the car and I plugged in my £25 Gendan lead with Vag-com last night. The laptop did communicate with the relevant controllers but there were no error codes thrown up.
Would the more expensive £300 lead from VAG-com have the ability to scan in greater detail or does it just provide more programming functionality etc?
It's actually my Mum's car and the light first came on after she filled up with Jet petrol. Was wondering if the car has picked up on this?

I tried to clear the error codes on the controller but with nothing to clear, the light is still on (this is how it works on my A6 so I assume it's the same)

Happy to take it to the garage but I like doing the vag-com thing myself first at least to diagnose in a very sad kind of way!

Any comments, advice etc greatly appreciated.

Thanks,
Grant

The_Laird · #2 28th February 2011, 12:05 PM

Grant - I'm so embarrased!

Only time I ever got this warning light was when the cats went (bothe were replaced and I think you have the receipts) and when I mysteriously got water into one of the spark plugs (but it was misfiring as well then).

Andy at A4 Audi usually doesn't charge for a diagnostic test, so I'd suggest you get your mum to take it there as he's on the doorstep

Singh · #3 28th February 2011, 01:39 PM

Sorry I can't help Titan but welcome to the forum. Jim's old car is lovely. I've heard/read that Jet fuel is very bad from am lot of different places...

Titan · #4 28th February 2011, 04:37 PM

Thanks for the welcome.
Jim, I would buy another car from you anytime so don't worry.
It's a 9 year old car so these things happen. It maybe misses you!
I'll get my Mum to take it into A4Audi and see what they say.
As for the full VCDS cable, I'm probably just looking for an excuse to buy it.....

jayzee · #5 28th February 2011, 05:19 PM

I too have heard that Jet petrol throws up an engine management light on quite a few cars.

I looked into this when my previous car did this very same thing after filling up.

Ska · #6 8th March 2011, 09:42 PM

IIRC a while ago there was a big hoo haa about tesco fuel that contained silicon that buggered the Lambda sensors. These don't always throw out codes when going south. Ask the guys at A4Audi to check the measuring blocks for these on VCDS to rule them out if nothing else.

Titan · #7 15th March 2011, 11:54 PM

Well the car eventually made it into A4Audi. I didn't have time to take it in so my Mum popped in with it today and they reset the light. They said they knew the car well and told her the light had probably come on as the car hadn't been driven much recently? Fair enough.
They didn't charge and the car has is still driving fine so fingers crossed it stays out.
That's the kind of customer service that will make me take the car back for all future work.

The_Laird · #8 16th March 2011, 05:14 AM

Pleased to hear that it doesn't sound like a major problem. They're right - since I had the S8, the A8 didn't get out much - especially in the really bad weather. But you'll find the customer service at A4Audi top notch - can't recommend them highly enough. Unlike most places, they actually do give a s**t!

Titan · #9 14th April 2011, 04:04 PM

Further update - The engine management light came back on again about a month ago. The car went back into A4 Audi. They reset the light and had a more detailed investigation. They said one of the sensors after the cat was flagging the error. Apparently they have seen this before when non Audi cats have been fitted. The cats are reasonably new I believe so it's just one of those things. The light hasn't been back on since (probably 3 or 4 weeks now)
Don't know if anyone else has had this issue so thought I'd just post up for info.
Price wise, genuine cats are an arm and a leg so I'd imagine most people would put on after market ones so just wondered if anyone has had similar issues?

Anyway, I took the car for a decent run at the weekend and it's running beautifully. My Mum loves it and I'm thinking about getting one for myself now even if getting the wee man in and out of the baby seat was more difficult than the B(loody awful) Class.
If I could just shift one of the others in the fleet............
How do I convince my wife that an S8 is the same size as her B-Class?

Singh · #10 14th April 2011, 07:51 PM

Just tell her its safer

A8 Doc on here may be able to program the sensor out for you or something. He does custom mapping.