Hello. I have a Vrs pre fl that is currently playing silly with me. I'm going to speak to the garage but your collective wisdom would be greatly appreciated.

Had the gas temp sensor replaced last Wednesday as it was faulty and drove 200+ trouble free miles upto Sunday. Drove to Birmingham (the cars longest stint at one speed for some time. My commute is country/A roads) no issue. Drove back no issue until I tried to lock the car and the alarm went mental. No response from the key to turn off or unlock. Eventually I did it manually and all was fine.

Got in the car an hour later, everything had reset to factory default. Mirrors are not individually adjusted, Windows are not auto close, radio reset (but still pairs to phone), time and trip mileage zeroed. Turned the key, car starts, ESP, tyre pressure and steering wheel lights are stuck on but go away after a minute of running. Car drives fine, all is well and the car locks.

Unlocked the car this morning, all is fine until I put the key into the ignition and everything dies. Turning the key does nothing.It's as if somebody has pulled the battery out. I checked the battery and the connections are fine, I got the spare key, opened the door and the cwar was fine, acting as if nothing happened. Started the car up, had the same dashlights stuck on for a minute and the car drove fine all the wwy to work.

I had somebody tell me a week ago that my car alarm had gone off a couple of times completely at random but whenever I went to it, the indicators weren't flashing as if it had gone off (the very first time, I heard the alarm turn off and saw the indicators still flashing).

Any ideas? I'm going to leave it an hour or so and then try start with the spare key again and see how it starts up but wondered if you guys had any ideas beforehand. Thanks in advance.

Sounds like the battery is dying

Sent from my Galaxy S5

Blimey that was a quick reply! I'll put the battery on test tonight and see how it looks. Thanks.

Has the alarm module ever been changed ? They start to fail about 6 years old onwards, the internal battery fails and can cause the main battery to drain.

I tested the battery yesterday night and it seems fine. After a drive from work, the battery was at 90%, had a pull of approximately 12.7v standing still and just over 14v when running so I think it is to do with the key battery. I have been using the spare key with absolutely no issues. I'll change the battery in the key and see what happens. Could be a long process of elimination.

From what you say and the fact it is behaving OK with the spare key.

Then your other original main key battery is duff or the little PCB inside has possibly got damp/corrosion causing it to transmit duff info.

The actual immobiliser transponer chip is solid state AFAIK so that shouldn't be the issue but you never know.

Spotted Timpsons in a local Saintsbury's are doing full blown keys with the buttons for what looked at a quick glance to be around £50!

Edited 14 July, 201510 yr by Defenderben

Now I'm not entirely sure that it is the key! I had the spare battery do the full switch off on me this morning. The electrics went dead when I turned the key, pressed unlock on the fob and everything came back on as normal, only the trip counter had been reset and the radio switched off. The time was fine. It is going to the garage at some stage this week to get VAG-COM'd and hopefully something will make sense after that. Might look at Timpsons though if both keys turn out to be the issue, thanks!