Audi 8L 2009 key not recognised

Audi A8L 2009 uk 4.2 tdi regularly serviced. Car was parked as normal.Suddenly flip key not recognised. I have tried battery in key and now Key has been checked and sending. Doesn't lock or unlock doors.only driver door unlocked constantly. Doesn't start from Electronic start button nor manual insert of key Water in driver and passenger footwell which has now been dried.seems to be from A/C as when drain disconnected bucket of water discharged. The MMI still works in all audio/Navigation etc but if car set up chosen says please start ignition? The control box under driver carpet was wet but shows no sign of corrosion. When disconnected MMI inoperable but when connected MMI initialises. Any suggestions? I don't have access to diagnostics as yet for any codes.

Did you replace the battery n the key? If so where did you gt the battery from? There are an awful lot of batteries that have high internal resistance on sale so although their open circuit voltage looks fine they don't work in the key. If that's the case get a brand new fresh battery from a known manufacturer and try that.

Other than that without an Auto-Scan it would be complete guesswork.

Audi A8L key not recognised

PetrolDave said:

Did you replace the battery n the key? If so where did you gt the battery from? There are an awful lot of batteries that have high internal resistance on sale so although their open circuit voltage looks fine they don't work in the key. If that's the case get a brand new fresh battery from a known manufacturer and try that.

Other than that without an Auto-Scan it would be complete guesswork.

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New Durable batteries tried both and key has been checked by key specialist and confirmed sending beam. Is there anyone in Edinburgh area that makes house calls to running autochanger?

CharlesS said:

New Durable batteries tried both and key has been checked by key specialist and confirmed sending beam. Is there anyone in Edinburgh area that makes house calls to running autoscan?

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Update today still no fob start but the flip key suddenly worked and engine started. There is a red key symbol warning light on dash. The steering is locked, ran engine for 10 mins on switching off the car it would not start as previous problem do not have access to scan. The MMI functions but wing mirrors don't set. Any thoughts support welcome.