chris666

No because I did try this a few days previously and it did not work

Further developments with the keys. I thought it would be a good idea to fit the keys with new Duracells to pre empt any problems in the future with dead batteries. After replacing the batteries, I thought I would try the keys to see if they would unlock the doors, which they wouldn't. However, after I'd put the key in the ignition and turned it , I took the key out and without thinking pressed one of the buttons on the key and it worked. Same thing with the spare key, wouldn't work to lock/unlock the doors, until the key had been turned in the ignition, it would not lock/unlock the doors. Thought this might bevof interest to anyone in the future with a similar problem.

Thanks for that. Maybe I'll give them a go

That sounds like the most likely explanation. At least I can still use the key to get in using the lock in the door handle. Don't think I want the expense of a new fob

No, the buttons aren't worn or stuck down. Both keys seem the same

I've used the battery from my second key which works fine,, but still no red light

No, it doesn't

Thanks for that . I have tried doing this, but still doesn't work

One of my two keys will no longer lock or unlock boot and doors. Works fine in ignition. Tried changing battery but has no effect. Car is 2017 Fabia