Description

Anti-Theft Alarm Description
The anti-theft alarm system is controlled by the Body Control Unit (BCU). The system alarms and disables the vehicle and monitors the vehicle status using door switches and ultrasonic sensors. The BCU also operates in conjunction with the Engine Control Module to disable the engine operation

When an alarm is triggered, the BCU operates the vehicle horns, an alarm sounder unit and/or a Battery Back Up Sounder (BBUS), depending on market to produce an audible warning In some markets, the BCU also operates the direction indicators to produce a visual warning when the system is armed and disarmed and/or an alarm is triggered.

On Korean vehicles only, the RF remote handset and receiver are replaced by an infra-red handset and receiver. The infra-red signal is received by the infra-red receiver located in the front interior lamp. An additional link harness is used as shown on the circuit diagrams and described in the following circuit operation. The feed for the receiver is taken from the rear interior lamp circuit - refer interior illumination description for details.

Anti-Theft Alarm Supply

Circuit supply
A feed from the battery positive terminal is connected on an R wire to the engine compartment fusebox. The feed passes through fusible links 3 and 8 and fuses 13 and 16.

The feed from fusible link 3 is connected on an NR wire to fuses 2, 20 and 21 in the passenger compartment fusebox. Fuse 21 supplies a feed to the contacts of the alarm sounder relay in the passenger compartment fusebox.

Fuse 21 also supplies a feed to the BBUS (where fitted), on a PB wire via header C0292 to keep the BBUS battery charged. If this feed is disrupted while the alarm system is armed, the BBUS is automatically activated. The BBUS is connected to earth header C0706 on a B wire.

The feed from fusible link 8 is connected on an NW wire to the passenger compartment fusebox and from the fusebox to the ignition switch on an N wire. The feed from fuse 16 is connected to the coil and contacts of the horn relay located in the engine compartment fusebox.

Where an alarm sounder unit is installed, a feed from fuse 13 is connected on a PN wire from the engine compartment fusebox to the passenger compartment fusebox. The feed passes through a diode and is connected to the coil of a relay integrated into the fusebox. The relay controls a power feed to the alarm sounder unit. Activation of the relay is controlled by the BCU via the IDM. The BCU communicates with the IDM using serial data messages on a SK wire via header C0292.

Ignition switch supply
When the ignition switch is in position II, the feed from fusible link 8 passes through the ignition switch to the passenger compartment fusebox on a Y wire where it passes through fuse 29. From fuse 29, the feed is connected on a GU wire to provide an ignition on supply to the BCU.

When the ignition switch is in the crank position III, the feed from fusible link 8 passes through the ignition switch to the passenger compartment fusebox on a WR wire and passes through fuse 23.

From fuse 23 the feed is connected on a WR wire to the coil of the starter relay in the engine compartment fusebox. The coil of the starter relay is connected on a BO wire from the engine compartment fusebox to pin C0662-5 on the BCU.

A second feed from fuse 23 is also connected on a WR wire to pin C0663-1 on the BCU. When the ignition switch is in crank position III, this feed signals the BCU to provide an earth path for the starter relay coil. This energises the coil closing the relay contacts and supplying power to the starter motor.