Hi all,

I've only ever used one of the keys for my RRS. Recently the plastic started to break up and then one of the tiny buttons broke. Not to fear, I thought. Grabbed the spare key. Nothing.

Ah ha I thought, it just needs charging. I'll just use a bit of wire to jumper the old key button contacts to get the car open and then I'll start it off the spare key. But... it won't start. Red immobiliser dash light just blinks. So, looks like the car doesn't recognise the key.

I thought the keys only used the internal battery for the lock/unlock circuit and the immobiliser was a different RFID circuit that needed no power?

I did manage to start the car using the spare key in the barrel and holding the old key next to it (fiddly and the Mrs wasn't impressed) but even after a 20 minute run the spare key wouldn't open/close the car - so either the battery is so dead that nothing can save it or the car has truly forgotten the key.

And thoughts or ideas? Does the car just need both keys re-learnt through something like SDD?

I know I'll need a new key with the rigmarole that entails, but I desperately need at least one key now

Thanks.

'tang

Had a similar situation. The second key that came with the car wouldn't start it until I had an Indie code it to the car. Note that you need to give them both keys as need to be done together. Takes a few minutes and cost about £30.

Changing the battery is possible but a bit of a faff so make absolutely sure the battery is duff first . Tape it or elastic band it to the old key when driving to charge it OR rest it against an electric toothbrush charger base overnight. (The toothbrush charger trick is mentioned on the Disco 3 site). 2008 MY Java Black TDV8 HSE

Thanks Paddi - I'll have a chat with my Indie round the corner.

Completely forgot to add an update. (Only a year late!)

Yes, once the second key was coded to the car it worked perfectly.

Make sure you alternate keys on a regular basis to ensure both remain charged up. 07MY RRS TDV6
Arctic Frost
Aspen Interior

Is this true for L494 's too? I like to keep one key pristine (sad, I know), so never use it ...

Can someone explain what they mean about charging the keys? I thought they were just simple replaceable batteries.

The keys have rechargeable batteries in, they charge when they are in the ignition switch.

So why does the handbook tell you how to change the battery if 'low battery' is warned in the display? (It says it is a CR 2032, the same as the replaceable battery in my last RR). Or are we talking about different key types? (Mine is a smart key).

Pre 2010 cars charged when the key was in ignition, the battery is soldered in place in these keys.

After 2010 they are keyless so can't recharge, but you just remove side, opposite to key blade to change battery.

Not sure if it will work with the RRS, but over on the BMW forums they reported that using the wireless charger for their toothbrush worked well. Might be worth giving it a shot ?



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EDIT:

Just had a quick look into it and the battery in the keyfob is 3.0v, the toothbrush chargers put out 1.2v/1.3v. To charge a battery properly you need to put a higher voltage through it than what it is rated at, hense why the alternator will kick out over 14v.

So based on that I would go with one of these:

https://www.amazon.co.uk/Upgraded-Wireless...B00C40OG22

These output 5.0v so rather than taking days it should only take an hour or so (if that with it being such a small battery).

Wow - never knew this & explains why my spare wouldn't start the car

Off to charge the spare...