Discovery II
ALARM SYSTEM AND HORN
DESCRIPTION AND OPERATION
86-4-7
Driver's door key lock/unlock switches
The BCU uses the driver's door key lock/unlock switches to activate and deactivate the alarm system. Two separate
switches are incorporated into the key lock of the driver's door.
Input/Output
The input from the driver's door key lock/unlock switches to the BCU is either zero volts or an open circuit. Zero volts
indicates the key lock is in the lock or unlock position. An open circuit indicates the key lock is in the centre position.
When the BCU senses an open circuit, it pulls the input high internally.
The driver's door key lock /unlock switches have a dedicated signal input to the BCU. This allows the BCU to identify
the lock/unlock position.
TestBook provides the ability to monitor the real time state of the driver's door key lock/unlock switches.
