I finally got round to fully testing the spare key that came with our car & am trying to work out what the fault is / how to fix it.
When bought I did a quick check to confirm the key unlocked / locked the car - which it did, so I didn't think any more about other than new buttons were required as it was very tatty. NB the car is a late 2006 tdv8 with the dash mounted ignitition barrel, but old style non flip key fob.

Yesterday I decided to full check it & discovered it will still lock / unlock the car fine, but it won't unlock the steering column lock !

With the main key, if you put the key in or close to the ignition barrel, you hear a solenoid unlock & if the key is in the barrel, you can then turn the key to the right - to positions 1, 2 or start. The steering column lock also unlocks & you can rotate the steering wheel.

With the spare key there is no solenoid click / clunk & the key / steering wheel can't be rotated.
However, if the main key is put near the ignition barrel while the spare key is in the barrel, the solenoid clunks & the spare key will rotate as it should, allowing the starter to be operated.
I'm assuming because the key will rotate, the blade must be OK & because the car will lock / unlock, the fob battery & radio transmitter must also be OK.

Is it possible that whatever operates the ignition & steering wheel lock solenoid (transponder ?), can fail separately to the radio transmitter function that operates the cars door locks ?
If yes, is it something that can be fixed without totally replacing the key ?

Thanks in advance for any help ! Paul,
2001 Discovery 2 TD5, 211,000 miles & climbing
2006 FFRR TDV8 Vogue 151,000 miles & now sold
Member of Midland (Land) Rover Owners Club, www.mroc.co.uk

Pretty sure that if you look inside your good key you will find a small triangular piece of plastic stuck inside ( that's the transponder for the wheel lock) - I'm guessing that it has fallen out of your spare key-when I replaced the batteries in mine I thought that it was just a piece of packing and threw it away - nearly an hour going thru my kitchen bin .

Oh dear - that sounds bad for me.
The spare key has a missing rubber "lock" button - where something small like that could probably escape ! Paul,
2001 Discovery 2 TD5, 211,000 miles & climbing
2006 FFRR TDV8 Vogue 151,000 miles & now sold
Member of Midland (Land) Rover Owners Club, www.mroc.co.uk