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Cyl 8 not firing, Audi S8 D2.

hi all Audi folks out there,

just joined to see if anyone can help me with my S8 issue!

I'll be brief,

i have had the S8 for 2 years! - never put a foot wrong, till the other week,
i have had sitting for around the 6-7 week mark as i was not using her,

i went to start last week! - and the battery was very low, in fact im sure it was not going to start, however, on its last breath, the car

jumped to life,

as it did, the CAT and Airbag light came on, and stay on 95% of time,

the engine sounded a tiny bit off, and after taking it to my local code reader dude, i got conformation that Cylinder 8 was not firing, all

plugs were checked, and indeed cyl 8 plug was dirty and charred, so it and all the others were cleaned.

so after a bit of reading, it seems a coil pack was the best item to replace, i did so today, and the issue is still there, i am Stumped and


i have confirmed that cynder 8's coil pack and spark plug is good. fuel to the cyl is also there,

my opinion - is that something has upset a circuit when the car jumped to life off the weak battery, car starts revs, pulls fine, hard to notice

its, but its there. im not driving it anymore, as i dont want raw fuel going down the cat.

fault codes from Bosch ESI tronic
-465a - supply voltage too high
-412c - combustion failure detected.
-4134 - combustion failure cylinder 8 detected.

Thanks in advance for any help!

Have you checked the output from the ecu at the coil multiplug?
You can test if it pulsing with a test light. You can also check the powers and earth while your there.

im guessing that is the part that you plug into the coil pack,

we checked this connector, and it looked good and fitted well, the cable dissapears off around th back of the engine block, i dont think im able to check where is goes without taking all the plastic parts off the top of engine etc..

i do have a mate coming over with mulit meter tomorrow to try and see if that power is at it, where does the cable dissapear off to? do you know?

can you reccommend a fault code reader/resetter - as a local comapany is taking 50 quid a time to read, and reset, -

do you have a idea on what it can be? i do suspect the issue is at the end of that connector to the coil palk.

thanks for your time, and rsponse,

1. Swap the coil pack with another cylinder.
2. Buy VCDS, it's the VERY FIRST tool you buy for any Audi and ESPECIALLY any A8/S8. About 200, plus a laptop which you hopefully have.

PS Are you on the A8parts forum - more relevant.  

i know its not the coil pack, thats been swapped and tested,

spark plug is good too, i am on the A8 parts forum, but need to reset my account,

i think the issue is at the other end of the cable that plugs into coil pack 8.

i will look into the VCDS right now,


is this the reader?

incidentally, im a IT pro, i can get almost any software, do i just need the interface cable and the software?

just been told this item is the tool to have and use for reading codes etc..

is this correct?

If it doesn't cost about 200 it's not genuine and is probably a waste of money and/or with old/cracked illegal software.

For a D2 you can use one of the older interfaces (no longer sold) and you might be able to get one of those secondhand for a bit less.

The VCDS software you just download from RossTech and the (genuine) cable acts as a dongle.

On the link there is a Distributor list. In the UK there are several, Gendan is one I recall. Contact one of them for precise advice.  

after speaking to someone from rossstech last night,

it was recommended i start with this and the lite version of the software, -

Now that I know you're Scotland, have a look here:

That would get you started with the free shareware version of VCDS-Lite, which only costs $99 to register.


so i have bought this from the UK supplier you mentioned. and will hope to get the part soon, then with any luck i can get this issue looked into further.

rickyates100 wrote:
Now that I know you're Scotland

ha! sorry, that was a cut and paste of the conversation from last night with ross tech!!

ha ha! - after saying i was in Scotland, the recommended gendan


That makes more sense.

I have a lead similar to that and a registered copy of VCDS-Lite. Though I came via another route - upgraded from a registered copy of VAG-COM bought long ago before VCDS existed.

At least you can do some things with that lead and the free version, though you'll probably want to pay and register fairly soon.

what is the best software to use,

i have found full ver's of

bosch ESI tronic, 2014.
VAG-com 409.1
VCDS 10.6.2

will they work with this hardware?

VCDS downloaded from Ross-Tech.

no problems, thats the one i will use,

thanks again for all your help people.

are there any further thoughts on why this issue has cropped up,



after speaking to A8,

there convinced its one of the ignition amplifiers, as a result, they are sending 2 out to me for 150 quid,

and if they dont work or fix the issue i can send them back for a full refund,

so i cant say no to that, - the saga continues, Forum Index -> Audi S8 (D2, D3 & D4) quattro
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