Has anyone else had this?

Out of the blue, the key won’t unlock the car, either via keyless proximity or the buttons themselves.

Thought it was a flat keyfob battery, but changed that this morning and it still won’t work. The red light on the fob doesn’t flash either, indicating that the car doesn’t recognise it.

The car does start, but I have to place the key in the little tray behind the parking brake for it to work.

I can’t lay my hands on the spare key at the moment, so having to lock/unlock via the app!

Help would be greatly appreciated!

If the red LED on the fob is not lighting up, the problem will likely be the new batteries - or the battery contacts inside the fob.

The LED indicator does not indicate that the car has recognised the fob - it indicates that a signal is being sent to the vehicle.

Did you make sure that any protective film on the new batteries were removed?

It’s actually the second battery I’ve tried: I found one in a drawer which I replaced the old one with, it didn’t work so assumed it was flat and bought a new one - still no joy.

Edited 19 December, 202519 Dec by chur1996

Are you using Duracell batteries? I avoid these as the bitrex coating applied to stop kids eating them acts as an insulator and can prevent a good contact in some devices....

Are you using 2025 cells - or are you trying to squeeze 2032s in?

It's not unheard-of for even 'new' cells to be faulty.

30 minutes ago, Warrior193 said:

Are you using 2025 cells - or are you trying to squeeze 2032s in?

It's not unheard-of for even 'new' cells to be faulty.

CR 2032 is the correct battery...

Yes, using CR2032s.

Brand manufacturers or budget manufacturers.

Hopefully this will help…

Thanks, I’ll give that a try 👍🏻

Turns out that the remote is indeed fussy about which battery it uses. Tried re-synchronising the key as per the guide above, no gain.

The new battery was indeed a Duracell battery, swapped for a new Panasonic battery and it started working immediately.

Yep, that tallies with what I've found - brands like EverReady, Duracell and off-brand Chinese rubbish either didn't work or lasted about 5 minutes.

Panasonic work and last longer than anything else, same in my motorcycle key fob FWIW.

Edited 22 December, 202522 Dec by CS363

i'm having a similar issue with my octavia. Randomly the car just locks when I get out of it and now it has started with the key not detected messages. Pressing unlock seems to get it going, but worringly this happens even when the wife is in the car with me (she has her own key on her). I have changed batteries in both fobs but they were to duracel... Once I get it open or started its usually ok for a couple of days or more but then randomly the same thing happens. Any thoughts?

Broken keyless Antenne?

4 minutes ago, Cairus said:

Broken keyless Antenne?

maybe, but not sure that would be intermittent or temporarily resolved with a button press?

On 29/01/2026 at 10:44, Jonny_123 said:

i'm having a similar issue with my octavia. Randomly the car just locks when I get out of it and now it has started with the key not detected messages. Pressing unlock seems to get it going, but worringly this happens even when the wife is in the car with me (she has her own key on her). I have changed batteries in both fobs but they were to duracel... Once I get it open or started its usually ok for a couple of days or more but then randomly the same thing happens. Any thoughts?

Try a Panasonic battery, worked for me.

3 hours ago, chur1996 said:

Try a Panasonic battery, worked for me.

I will try that. thx.