Key issues

[willp86]

First time post here after buying 1999 E39 B10 V8 no.416 at the beginning of the year. I've been meaning to do a general post on the car for a while, but the year has disappeared.

I've had some key gremlins since buying the car. The car came with four keys: two remote keys (old style, with a removable CR2016 battery), one service/valet key, and one slim wallet-type key. Great, you might think.....

One of the remote keys works perfectly. The other seems dead - I've replaced the battery to no avail. The little red LED doesn't flash at all when pressing any of the buttons.

Both the non-functioning remote key and the valet key unlock the car at the door. However, as soon as the door is opened, the alarm goes off. This can only be stopped using the functioning remote key.

Neither of these keys will actually start the car. They will move through all the positions - fine if you just want to sit in the car and listen to the radio(!) - but when turned to ignition position..... nothing.

At the moment this is not critical because I have one functioning key, but if / when that fails it's going to cause an issue!

Any help / advice much appreciated!

[Charles]

I'll have a go.

The remote keys contain a transponder that talks to the immobiliser, but the service and wallet key don't - hence why the latter will open the car and engage the ignition but not start the car or disarm the alarm.

As for the non-functioning remote key, it may be that it needs coding to the car. I believe that the key holds certain information if the battery runs down but not sure for how long and it may be that one of them has kept it but the other hasn't. This requires a process of pushing certain buttons on the remote whilst the key is in the ignition. You should be able to Google it to find the correct procedure.

However, this doesn't explain the lack of red light when buttons are pressed. It might be that the bulb has failed but if the key is not coded, then you won't know either way.

I hope this helps

[440]

However, as soon as the door is opened, the alarm goes off. This can only be stopped using the functioning remote key.

Locking the car using the remote will arm the alarm, so if you want to use the valet key you need to lock the car using the cylinder lock. If the alarm goes off you won't be able to start the engine with any key unless you stop the alarm using the remote.

[willp86]

Thanks for both your replies on this. I've come to the conclusion that my spare remote key is dead, so that is another one for the issues list.

Locking and unlocking with the valet key solves the issue of the alarm going off - thanks for your help with that. However, it still won't start the car (neither will the wallet key). Unfortunately, it's looking like a trip to the main dealer!

[BarryM]

The E39 is meant to charge the key battery when in the ignition but the batteries are getting so old now they’re starting to fail. One of my keys wouldn’t hold a charge so I took a chance on an ebay seller who replaced it for £17. I can post details if you’re interested.

[willp86]

Thanks Barry - very kind but my key is actually the older type with the replaceable battery (the car is 1999 - pre-LCI). A new battery hasn't made any difference (not even registering a red led when the buttons are pressed) so suspect it's one for the bin!