Intermittent central locking issues

[Court X3]

So the other day the central locking started acting up in the car. While trying to lock the doors it wouldn't activate until getting back into the car and inserting the key then getting out and shutting the door.

Any ideas on where to start looking? I've done a little research and came up with little.

[AzNMpower32]

When was the last time you replaced the battery on the key?

[Court X3]

Batteries, have never been replaced although one key is only a year old. This wouldn't need a trip to the dealer to reset the key after the replacement or to be replaced right?

[AzNMpower32]

I doubt it. I've replaced it on my mother's Comfort Access and it worked fine afterward.

[trapdoor]

Originally Posted by AzNMpower32

When was the last time you replaced the battery on the key?

Thought the batteries in the X3 keys were non-replaceable and rechargeable Certainly in the UK/EU the keys are. They are charged via an inductive loop charging cct in the steering lock mechanism - may even be the same one that energises the RFID for the immobiliser.

However I'd say that it was low battery that could cause the issues. Mrs doesn't drive the X3 and her key is hardly ever used. Have had an issue with her key once where it wouldn't open the door, but after using it in place of mine for a couple of weeks it is now working fine - just needed charging.

[AzNMpower32]

Yes, the battery charges while the key is in the ignition, but I can't imagine having a key with batteries that cannot be replaced.

[trapdoor]

Originally Posted by AzNMpower32

Yes, the battery charges while the key is in the ignition, but I can't imagine having a key with batteries that cannot be replaced.

Well, I think anything is possible but I'd wager that once you had sliced open the fob which looks like it has been ultrasonically welded, you'd be faced with unsoldering a hard to source button NiMH or NiCD cell - which would be easily damaged by 'iron' soldering back into the fob electronics.

They certainly aren't user replaceable unless you like a challenge.

Probably if you had a totally dead one, then you don't have much to loose if you screw it up

[AzNMpower32]

I guess it's completely different from the Comfort Access fob (which isnt meant to be recharged) then. Hopefully I will never need to find out!

[trapdoor]

Originally Posted by AzNMpower32

I guess it's completely different from the Comfort Access fob (which isnt meant to be recharged) then. Hopefully I will never need to find out!

Never seen one of those - 'Comfort Access' isn't something that seems to be readily available in the UK - no idea why as I really like the idea of it. Think it's starting to appear now but there were issues with licensing of low power radio devices a few years ago, particularly as some car fobs were put on the same frequency as UHF amateur and PMR radio. So park anywhere within 500m of a transmitter and you couldn't open your car or unset the alarm

[AzNMpower32]

A slight bit off topic here, but the Comfort Access keyfob on the newer Bimmers looks just the same as the ordinary ones, except the front door handles of such-equipped cars have ridges on the top for the keyless locking.