Probably FOB battery. New one doesn't always mean good one. VCDS will show if this is the case.
A8 not recognizing key fob when approaching
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A8 not recognizing key fob when approaching
My 2008 A8L and is not recognizing the key when I approach. This is sporadic. Sometimes it unlocks the car and other times it doesn't regardless of which door I am close to. It is happening on both of my key fobs and I have tried replacing batteries. Once inside the car I can use the start button without putting the key in the ignition but my wife has even had times when she has to insert her key. Any ideas? I'm assuming there is an antenna somewhere and maybe it is loose. Thanks for any help.
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I went to the stealer numerous multi-hour days over this and a few other items with no remedy. Finally they ordered an antenna replacement, I think there are four total.
Anyhow, the tech realized my car battery was weak and croaking out on him while in the service bay. Apparently when the battery goes dead or close to it, the car has a safety measure which includes shutting certain things down so something 'bad' doesn't happen. When this happens, I was told the tech needs to 'reset' or 'reprogram' the auto lock/unlock feature.
In the end, they 'reprogrammed' my rig and didn't even need the antenna they had. The auto lock/unlock now works, albeit with some inconsistencies due to my weak battery.
I scratched my head and asked about replacing my battery and if in doing so i would be without auto lock/unlock again due to the battery being disconnected. The service manager put his hands up and said maybe.
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I agree - could very well be the main battery.
VCDS should tell you about quiescence due to low voltage and/or the module being an issue.
Also periodically use the key in the ignition.
Apparently, or so I was told, it syncs the system - every time mine got flaky this resolved it.
VCDS should tell you about quiescence due to low voltage and/or the module being an issue.
Also periodically use the key in the ignition.
Apparently, or so I was told, it syncs the system - every time mine got flaky this resolved it.
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+2; and plus most all the above as other possibles
Can be car battery. Below 50% indicated charge (IIRC) and power mngt system cuts off keyless entry as among the early things it sacrifices. If you have a VAG-COM, that cut off shows up under the power mngt module as the lowest stage.
Also can be any of the other things mentioned in replies or OP. Can also be the key (batteries aside) if it gets dropped, washed or otherwise abused enough. Like cell phone connectivity, I think sometimes folks jump to the car side a lot, even if the small device is the thing most obviously abused by everyday use. Here the OP says it affects both keys though, so less likely. Takes me back to maybe the main car battery if keyless either works or not, like a light switch. I would expect antenna issues, weak fob batteries etc. to be more variable by range.
Last item: watch out for cell phone RFI interference. My key absolutely hates being in the same pocket as my iPhone. They have to go in opposite pockets or I have to take one or the other out when they get into same pocket as the day goes on. Otherwise, door frequently just stays locked until I separate the electronic kids.
Also can be any of the other things mentioned in replies or OP. Can also be the key (batteries aside) if it gets dropped, washed or otherwise abused enough. Like cell phone connectivity, I think sometimes folks jump to the car side a lot, even if the small device is the thing most obviously abused by everyday use. Here the OP says it affects both keys though, so less likely. Takes me back to maybe the main car battery if keyless either works or not, like a light switch. I would expect antenna issues, weak fob batteries etc. to be more variable by range.
Last item: watch out for cell phone RFI interference. My key absolutely hates being in the same pocket as my iPhone. They have to go in opposite pockets or I have to take one or the other out when they get into same pocket as the day goes on. Otherwise, door frequently just stays locked until I separate the electronic kids.
Last edited by MP4.2+6.0; Mar 9, 2013 at 08:16 AM.
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From: A2, MI, USA
recognizing the key again
Had a similar problem just this week where my car said that the key was not recognized (it was in my coat pocket). I found that using the key fob to lock/unlock the doors got it to be recognized again.
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From: A2, MI, USA
different pockets
Last item: watch out for cell phone RFI interference. My key absolutely hates being in the same pocket as my iPhone. They have to go in opposite pockets or I have to take one or the other out when they get into same pocket as the day goes on. Otherwise, door frequently just stays locked until I separate the electronic kids.
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