VW Polo - Key suddenly won't start the engine.

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Tue 30 Aug 2022 11:57
VW Polo - Key suddenly won't start the engine. - SunriseSunset

Hi, I've found this forum through an online search whilst trying to understand the cause of the problem.

I have two keys for my VW Polo. The key with a remote (which I have always used) has suddenly stopped working. It will turn the car over but won't start, two warning lights appear on the dash - diesel engine pre glow and the other is a car and key symbol.

The remote has never worked (I assume a dead battery) so I have always manually opened the doors with the key in the door.

I cant understand why the key would suddenly stop working to start the engine. My spare key (without a remote) still works and no warning lights appear which suggests the problem is with the key itself and not the immobiliser(?)

As the remote has never worked since owning the car the last six years, I assume the battery has always been dead.

Does this sound like a simple battery problem? Is this something I can replace myself or best to take to the car dealer?

If it is the battery, will the key need to be programmed?

Thank you in advance for any help with this problem.

Edited by SunriseSunset on 30/08/2022 at 11:58

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Tue 30 Aug 2022 12:58
VW Polo - Key suddenly won't start the engine. - elekie&a/c doctor
If the key with remote has stopped working, it’s possible there is a problem with the immobiliser chip fitted in the key . Have you taken the key apart recently? The battery in the key is solely for the remote locking function. It does not affect the starting of the car .
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Wed 31 Aug 2022 09:55
VW Polo - Key suddenly won't start the engine. - SunriseSunset

Hi, the key hasn't been taken apart recently. I've never bothered to replace the battery as I just got used to opening the doors manually, rather than with the remote.

I've just had a new key cut, no remote - however I am having the same problem with the new key. I cant work out why my spare key still works but the new one doesn't.

I was told I can programme the key myself - I thought I'd have to take it to the car dealer to do that. If this is right I'd have to get the remote problem sorted first, hopefully it just needs the battery replaced.

Edited by SunriseSunset on 31/08/2022 at 09:56

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Wed 31 Aug 2022 10:13
VW Polo - Key suddenly won't start the engine. - elekie&a/c doctor
A new key needs to be programmed via the diagnostic system . You can’t do it yourself. The remote locking part of the key and the battery has no relation to starting the car.

Edited by elekie&a/c doctor on 31/08/2022 at 10:15

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Wed 31 Aug 2022 14:36
VW Polo - Key suddenly won't start the engine. - Brit_in_Germany

Maybe the battery in the key with the remote has leaked and caused damage to the immobilisation chip circuitry. Maybe worth opening the fob and seeing if there is any chemical residue which you could clean out.

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