LR3/Disco 3
allow time for the vehicle interior to settle.
If any of the hinged panels, except the driver door, is open, the CJB arms in the perimeter mode, but ignores the open
hinged panel as an alarm trigger and generates a mislock sound. On a superlocked vehicle with a volumetric sensor
installed, if the open hinged panel is a door or the tailgate, the CJB remains in the perimeter mode instead of transitioning
into the volumetric mode. If the open hinged panel is subsequently closed, and remains closed for 1 second, the CJB then
includes it as a valid alarm trigger and, where appropriate, transitions into the volumetric mode.
Disarming
The CJB disarms the anti-theft alarm system when it receives an unlock request from the remote handset.
When the vehicle is unlocked using the door key lock, the CJB disarms the anti-theft alarm system if, within 12 seconds, a
valid key is installed in the ignition switch or an unlock request is received from the remote handset. The CJB detects the
installation of a valid key from the transponder coil around the ignition switch. During the 12 seconds delay, only the hood
ajar switch remains as a valid alarm trigger, and the instrument cluster speaker is pulsed at 0.5 second on, 0.5 second off.
If, within the 12 seconds, a valid key is not installed in the ignition switch, there is no unlock request from the remote
handset, or the hood is opened, the CJB enters the alarm mode.
The CJB can selectively disarm parts of the anti-theft alarm system, to prevent nuisance alarms being triggered, as
follows:
On vehicles with park heating and cooling, the CJB disarms the volumetric sensor, where applicable, when park
heating or cooling is activated. This prevents air movement, produced by the blower, from triggering the alarm.
The CJB re-arms the volumetric sensor when park heating or cooling is de-activated. The CJB disarms and re-
arms the sensor in response to the Air Conditioning (A/C) alarm level request message which the Automatic
Temperature Control Module (ATCM) outputs on the medium speed CAN bus.
When the anti-theft alarm system is armed in the volumetric mode, if the vehicle battery voltage decreases to less
than 9 volts the CJB will transition into perimeter mode by disarming the volumetric sensor and the tilt sensor. This
prevents false alarms caused by the sensors not operating below 9 volts.
Where a BBUS is installed, if the vehicle battery voltage decreases from 9.5 to 9 volts in more than 30 minutes,
the CJB will disarm the BBUS and, if necessary, use the horns as the audible warning. This prevents false alarms
caused by the CJB not supplying the heartbeat signal to the BBUS below 9 volts, which the BBUS would interpret
as a tamper condition. If the voltage rises above 9.5 volts the CJB re-arms the BBUS.
If the vehicle is unlocked using the remote handset and, within 1 minute, a hinged panel is not opened or a valid
key is not put in the ignition switch, the CJB automatically relocks the vehicle and re-arms the anti-theft alarm
system. This prevents the vehicle being left unlocked and disarmed by accidentally pressing the remote handset
unlock button.
Alarm
When the alarm is triggered, audible and visible warnings are produced by the CJB. Audible indications are produced
using the horns or the BBUS. Visible indications are produced using the hazard flashers.
If the BBUS is used for the audible indications, the BBUS cycles the sounder on for 30 seconds and off for 5 seconds. If
the alarm trigger is still present after the 5 seconds off period, the cycle of 30 seconds on, 5 seconds off, is repeated. The
BBUS operates for a maximum of 10 cycles for each alarm trigger source, or until it receives a disarm signal.
If the horns are used for the audible warning, the CJB cycles the horns on for 30 seconds and off for 5 seconds. If the
alarm trigger is still present after the 5 seconds off period, the cycle of 30 seconds on, 5 seconds off, is repeated. The
CJB operates the horns for a maximum of 10 cycles for each arming cycle, or until it receives a disarm signal. The 10
cycle limit prevents damage to the horns from excessive use.
During the on period, the BBUS sounder or the horns are pulsed at 380 milliseconds on, 380 milliseconds off. The hazard
flashers are also pulsed at 380 milliseconds on, 380 milliseconds off, in sequence with the audible warning.
The anti-theft alarm system transitions from an armed mode to the alarm mode if:
The hood, a door or the tailgate is opened.
The volumetric sensor signals an alarm condition.
The tilt sensor signals an alarm condition.
A non valid key is detected in the ignition switch. There is a 0.4 second delay between recognition of a key being
installed in the ignition switch and identification of the transponder, to allow sufficient time to interrogate the key.
The vehicle is unlocked using the door key lock and the CJB does not detect a valid key in the ignition switch or
