Alarm System

The alarm system comprises the following components:

• RF receiver.
• RF transmitter.
• BCU.
• IDM.
• Door switches, door lock switches and bonnet switch.
• Battery backed-up sounder (BBUS).
• Status LED.

On non NAS vehicles, power supply for the alarm sounder and the battery BBUS is provided through two relays in the passenger compartment fuse box. Each of the coils of the alarm relays are directly connected to the IDM which controls their operation under the direction of BCU signals received via the serial data bus.

On NAS vehicles, an audible warning is provided through operation of the vehicle horns. The BCU provides an earth path for the coil of the horn relay to initiate vehicle horn operation. See ALARM SYSTEM AND HORN .