Battery coding looks ok, but wouldn't cause the car not to start.
Is it just cranking and cranking?

If you crank can someone see if gas/air is pumping from the exhaust?
You have fuel so I wonder if the shut-off / throttle is not opening?

Maybe someone who knows more about the 4.2 tdi can say.

Weird that there is no code.
Also why is there no Address 25: Immobiliser on your logs? Can you connect to it manually by choosing 25 ?

Any sign of water under the drivers footwell carpet?

Carpets are dry!

I have allready looked into the immobilizer and apparently if you have keyless entry you dont have an immob unit , it is done by 05 access module.

Thanks

I have keyless entry and start and have 05 and 25.
What do others have?

00-Steering Angle Sensor -- Status: OK 0000
01-Engine -- Status: Malfunction 0010
02-Auto Trans -- Status: OK 0000
03-ABS Brakes -- Status: OK 0000
05-Acc/Start Auth. -- Status: Malfunction 0010
06-Seat Mem. Pass -- Status: OK 0000
07-Control Head -- Status: OK 0000
08-Auto HVAC -- Status: Malfunction 0010
09-Cent. Elect. -- Status: Malfunction 0010
0F-Digital Radio -- Status: OK 0000
15-Airbags -- Status: OK 0000
16-Steering wheel -- Status: OK 0000
17-Instruments -- Status: OK 0000
18-Aux. Heat -- Status: Malfunction 0010
19-CAN Gateway -- Status: Malfunction 0010
1E-Media Player 2 -- Status: OK 0000
25-Immobilizer -- Status: Malfunction 0010
28-HVAC, Rear -- Status: Malfunction 0010
34-Level Control -- Status: Malfunction 0010
36-Seat Mem. Drvr -- Status: OK 0000
37-Navigation -- Status: OK 0000
38-Roof Electronics -- Status: OK 0000
42-Door Elect, Driver -- Status: OK 0000
46-Central Conv. -- Status: Malfunction 0010
47-Sound System -- Status: OK 0000
4F-Centr. Electr. II -- Status: OK 0000
52-Door Elect, Pass. -- Status: OK 0000
53-Parking Brake -- Status: Malfunction 0010
55-Xenon Range -- Status: Malfunction 0010
56-Radio -- Status: OK 0000
57-TV Tuner -- Status: Sporadic communication error 1000
61-Battery Regul. -- Status: Malfunction 0010
62-Door, Rear Left -- Status: OK 0000
67-Voice Control -- Status: OK 0000
72-Door, Rear Right -- Status: OK 0000
76-Park Assist -- Status: Malfunction 0010
77-Telephone -- Status: OK 0000

At 11.55V battery does not look too good while doing scan, this could be dropping to under 10V while cranking and preventing car from starting. Looking at voltage reading and supply voltage errors I would say it's either discharged, bad or poor connection for +12V or ground.

Charge battery, measure battery voltage with multimeter at the battery and on the car, check how much voltage drops while cranking.

I have keyless and also have both 05 and 25. is the immo listed on the installation list of the can gateway, maybe the car is not looking for the immo so will not start. Not sure if simply enabling it on the can gateway is enough though

(old installation list below)

00-Steering Angle Sensor -- Status: OK 0000
01-Engine -- Status: OK 0000
02-Auto Trans -- Status: OK 0000
03-ABS Brakes -- Status: OK 0000
05-Acc/Start Auth. -- Status: Malfunction 0010
06-Seat Mem. Pass -- Status: OK 0000
07-Control Head -- Status: OK 0000
08-Auto HVAC -- Status: Malfunction 0010
09-Cent. Elect. -- Status: OK 0000
13-Auto Dist. Reg -- Status: Malfunction 0010
15-Airbags -- Status: OK 0000
16-Steering wheel -- Status: OK 0000
17-Instruments -- Status: Malfunction 0010
19-CAN Gateway -- Status: OK 0000
1D-Driver Ident. -- Status: OK 0000
1E-Media Player 2 -- Status: Malfunction 0010
25-Immobilizer -- Status: Malfunction 0010
28-HVAC, Rear -- Status: Malfunction 0010
34-Level Control -- Status: OK 0000
36-Seat Mem. Drvr -- Status: OK 0000
37-Navigation -- Status: Malfunction 0010
38-Roof Electronics -- Status: Malfunction 0010
42-Door Elect, Driver -- Status: Malfunction 0010
46-Central Conv. -- Status: Malfunction 0010
47-Sound System -- Status: Malfunction 0010
4F-Centr. Electr. II -- Status: Malfunction 0010
52-Door Elect, Pass. -- Status: OK 0000
53-Parking Brake -- Status: Malfunction 0010
55-Xenon Range -- Status: Malfunction 0010
56-Radio -- Status: OK 0000
57-TV Tuner -- Status: OK 0000
61-Battery Regul. -- Status: Malfunction 0010
62-Door, Rear Left -- Status: OK 0000
72-Door, Rear Right -- Status: OK 0000
76-Park Assist -- Status: Malfunction 0010
77-Telephone -- Status: OK 0000

Had to leave on the path for now, working in Surrey now till thursday , i am going to have one last go thursday night when i get home , if it still wont start i will have to get it recovered to an audi specalist on Friday morning.
As luck would have it my parents have gone on holiday so i have my dads car to get about.
Will update with how i get on thursday/friday.

Thanks again for all the advice , will investigate the missing immobilizer in the mean time.

Thanks
PWACKA8

See below regarding immobilizer on address 05

http://wiki.ross-tech.com/wiki/index.php/Immobilizer

Which cars have Immobilizer?

In the US/Canada, most VW/Audi models prior to model year 2000 did not have Immobilizer.
In the rest of the world, Immobilizer usage was introduced earlier.
In most vehicles the Immobilizer Control Module is integrated into the Instrument Cluster.
Upper Class Vehicles like the current Audi A5, A6, A8 and Q7 have a separate Immobilizer in Address 05 - Acc/Start Authorization.
Many of the older non-US market vehicles as well as some US-Market VW Golf Cabriolet (1E) and VW Transporter/Eurovan (7D) have a separate Immobilizer Control Module Address 25 - Immobilizer

Interesting, I did a quick google and found a US S8 without address 25

http://www.audiworld.com/forums/a8-s...d3-s8-2861527/

The RossTech site is very US centric, its possible that US based A8 D3s are missing address 25 but EU ones should have address 25.

Just checked another VCDS scan I have and it has the immob at 25 too.

Interestinly I have just looked at my scans and the early ones have 25 & 5

but after I fitted a a acc compatible gateway 25 is no longer listed

How strange :Confused: