Central Control Unit

Have read through the list of things this does on the Rave CD and it seems to do loads

Below is copied from the CCU page

The CCU is located on the back of the passenger
compartment fusebox below the fascia. The CCU is
responsible for controlling the following functions:
• Transit mode
• Anti theft alarm system
• Windscreen wipers
• Courtesy lamp delay
• Door open warning light
• Rear fog guard lights
• Lights on alarm
• Catalyst overheat
• Seat belt warning
• Handbrake warning
• Overspeed warning
• Rear screen wiper
• Tail door window
• Heated rear window

So my question is, are the Alarm fobs coded to this or does the Alarm receiver do the job and if I need to change the CCU will it also change the mileage on the speedometer