The Valet key will open/start any year Rangie, but you may have a problem if the alarm is set then triggered. Under certain circumstances, the BeCM may determine that someone tried to steal your Rover, and will disable ('immobilise') the engine. It will ask you to press the button on the fob to disarm the system. If you don't have a working fob, you may be out of luck... In some cases, some people have been able to use the EKA procedure (see
this) to get things going again.
There is some debate if the vehicle can actually be superlocked/immobilized without the fob, so it may be a moot point, but it is something to think about/research further...
Here is some more info from the Workshop Manual:
There are six modes of vehicle locking used on the vehicle: sill locking, slam locking, key CDL locking, remote CDL locking, key superlocking and remote superlocking. The BeCM controls all locking and alarm functions.
Sill locking is achieved by depressing either of the front door sill buttons when both front doors are closed. All doors and the tail door will CDL lock, but immobilisation and the alarm system will not enable. Sill locking operates independent of key-in and ignition state. On vehicles from 96.5MY an accidental sill locking feature was introduced to prevent accidental sill locking of the doors. If the sill button on either of the front doors is depressed within 0.5 seconds of that door being closed, all doors will unlock. If the ignition is on and the inertia switch is tripped, all doors, including the tail door, will unlock. Further re-locking is prevented until one of the front doors is opened with the key removed from the ignition.
Slam locking is only available on vehicles up to 96.5MY. Slam locking is performed by depressing either of the front door sill buttons with the door open and then closing the door. All the doors and the tail door will CDL lock and the alarm will be armed in perimetric mode with cranking disabled and immobilisation activated. If the vehicle is slam locked with the key in the ignition or the ignition on, all doors will immediately unlock when the door is closed.
Key CDL locking. A single turn of the key in the driver’s door lock towards the rear of the vehicle will cause all the doors including the tail door to CDL lock. The alarm system will enter perimetric mode with cranking disabled and immobilisation active.
Remote CDL locking. A single press of the lock button on the remote handset will cause all the doors including the tail door to CDL lock. The alarm system will enter perimetric mode with cranking disabled and immobilization active.
Key superlocking. A double turn of the key within two seconds in the driver’s door lock towards the rear of the vehicle will cause all the doors including the tail door to superlock providing that they and the bonnet are closed. The alarm system will enter perimetric mode with cranking disabled and immobilisation active.
Remote superlocking. A double press of the lock button within two seconds on the remote handset will cause all the doors including the tail door to superlock providing that they and the bonnet are closed. The alarm system will have crank disable and immobilisation active and if all windows and sunroof are closed the volumetric and perimetric systems will be activated. If any of the windows or the sunroof are open, then only the perimetric system will be activated. Remote superlocking is prevented if the key is in the ignition.