Audi A6 flat battery error

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Mon 12 Feb 2007 20:45
Audi A6 flat battery error - Peter D
Audi A6 1.8T 98 R plate AEB 20 valve engine 40,800 miles. I have been keeping this car down south at my MinL?s and on a recent visit the battery was completely fault ( five years old ) I charged the battery and eventually it fired up with no errors but the battery would not hold it?s charge so popped into a local garage and had a new battery Exide 096 fitted. The Ecu came up ?OK? ( The Actual ECU diagnostic priority message ) with no reported faults but the Air con digital temp displays for NS/OS started flashing when turned on and continues for 4 mins. This problem does not appear to effect the A/C operation although it is too cold to check the freeze/compressor function. I popped to a local Audi VW specialist and he fired up the ECU diagnostics using EOBDC via a Snap-On Canbus interface and discovered no faults reported anywhere. He cleared all systems to make sure but the faulty flashing continues for 4 mins after every start up. I have tried a battery disconnect but it still remains. Any ideas welcome.

Regards Peter
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Mon 12 Feb 2007 21:38
Audi A6 flat battery error - Screwloose
Peter

An EOBD interface [CAN or not] won't talk to the climate ECU. You'll need someone with a proper scanner or VAG-Com.
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Tue 13 Feb 2007 09:33
Audi A6 flat battery error - Peter D
Very interesting Screwloose. He appreared to know exactly wahat he was doing and used Eobd and OBD comms to talk to the ECU's. He runs a long established VAG/Audi Specialists in Sully south wales and has an Audi himself so I am alitlle surprised that you say he could not talk to it but as he did not identify the actual problem them that may he that he could not actually communicate with it using the Snap-On. He had all the right dongles and interfaces. Regards Peter
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Tue 13 Feb 2007 11:37
Audi A6 flat battery error - Screwloose
Peter

I doubt that he was using EOBD then. That can only talk to the powertrain control ECUs for mainly emission-related matters and only really notices air-con as a load factor.

If he's a VAG specialist, he would almost certainly be using a manufacturer-specific interface pod - he wouldn't get far without one....
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Tue 13 Feb 2007 15:11
Audi A6 flat battery error - Peter D
He mostly used OBDCII to interigate the ECU's and said there was no faults reported. He switched to EOBDC to see if anthing else popped up. He had all the right pods, but could not point me what or where the fault may be. It does sound as though he could not see the A/C Ecu as you said. OK he did not charge me much but he must have known that he would not be able to see it. Are there other Snap On users that not been able to see the A/C ECU. ?? Regards Peter
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Tue 13 Feb 2007 15:54
Audi A6 flat battery error - Screwloose
Peter

What is OBDCII? I see a lot made of these meaningless acronyms by tat-sellers on e-bay. No UK-spec VAG would be programmed to use it and, even in the US, it would again be emissions-only. In the UK; OBD II is useless to anyone without a 1996 2.5 Volvo.

I've no idea what the dear old red door-stop can talk to these days - I progressed beyond it's, desperately limited, capabilities years ago. [Having seen the latest update charges, I doubt I'll be the only one! £799 a pair; every few months for that?]

I'm just surprised that a VAG specialist doesn't have VAG-Com. There are upwards of twenty different ECUs on your A6 - everything from the immobilizer to the left-hand front door ECU. How he can re-configure the soft coding; or even re-set the service indicator, without something like that is difficult to imagine.
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