Anti-Theft - Passive: Description and Operation

Anti-Theft - Passive

DESCRIPTION

Introduction
The passive anti-theft system consists of an engine immobilisation system which prevents unauthorised starting of the vehicle. The system is controlled by the Engine Control Module (ECM) and the Central Junction Box (CJB). Re-mobilisation is achieved via a transponder in the remote handset, which is read by a transponder coil mounted around the ignition barrel.

A visual deterrent is provided by an instrument cluster mounted LED. The flashing sequence of the LED reflects the status of the engine protection system, and is controlled by the CJB.

OPERATION

Power Distribution
Feed from the positive battery terminal (C0192) is supplied to fusible link 11E, fusible link 16E, and fusible link 17E on an R wire. All are located in the Battery Junction Box (BJB) (C0632). Fusible link 16E (C0570) provides a constant battery feed to the Central Junction Box (CJB) (C0583) on an NG wire.

Fusible link 17E (C0570) is connected to fuse 43P of the CJB (C0583) on an NR wire. Fuse 43P (C0585) provides a constant battery feed to the Radio Frequency (RF) receiver (C0049) on a GW wire.

Fusible link 11E (C0570) is connected to the ignition switch (C0028) by an N wire. When the key is placed in the switch, current flows across the switch to the CJB (via fuse 40P) (C0582) on an LGW wire. When the ignition switch is turned to the auxiliary position, current flows across the switch (C0028) to the CJB (C0582) on a W wire. The CJB (C0585) is provided a ground path via a B wire.

Transponder Coil
The CJB (C0580) provides a feed to the transponder coil (C2524) on a G wire. The coil transmits data at a frequency of 125 kHz. When the ignition key comes within range of the transponder coil, the transponder within the ignition key transmits vehicle identification data to the coil. This is relayed back to the CJB (C0580) on an R wire.

Engine Control Module

V6 and V8
The CJB (C0580) communicates with the ECM (C0635) via the high speed CAN bus on YN (high) and YB (low) wires.

Alarm Indicator
Illumination of the instrument cluster mounted alarm indicator LED (C0230) is controlled by the CJB (C0580) on a BS wire. By switching the power supply on and off, the CJB can control the flashing sequence of the LED. The LED is provided a ground via the instrument cluster (C0230) on a B wire.