Volumetric Sensor

Volumetric Sensor

The volumetric sensor monitors the inside of the vehicle by emitting a series of ultrasound pulses, and measuring the profile of the returned echo. The sensor (C0359) is located the centre of the headlining, and is provided a constant battery feed from fuse 43 of the passenger compartment fuse box (C0586) on an RW wire.

When the anti-theft alarm is armed, the BCU (C0661) 'switches on' the volumetric sensor by providing a pulsed voltage signal to the tilt sensor (C0960) on a BS wire. This signal is relayed to the volumetric sensor (C0359) on a BW wire. If the volumetric sensor detects movement within the passenger compartment, it provides a feed to the BCU (C0661) on a BY wire. The volumetric sensor (C0359) is earthed on an N wire.

Tilt Sensor

The tilt sensor monitors the angle of the vehicle. If the angle of the vehicle moves more than the thresholds outlined in the Description section, the alarm will be triggered. The sensor (C0960) is located beneath the front passenger seat, and is provided a constant battery feed from fuse 43 of the passenger compartment fuse box (C0586) on an RW wire. When the anti-theft alarm is armed, the BCU (C0661) 'switches on' the tilt sensor (C0960) by providing a pulsed voltage signal on a BS wire.

When the anti-theft alarm system is activated, the tilt sensor (C0960) provides a voltage pulse to the BCU (C0661) on a BU wire. If this isn't received within a set time, the BCU determines that the unit is defective.

If the tilt sensor is triggered, it provides a voltage pulse to the BCU (C0661) on a BU wire. Recognising this signal, the BCU (C0661) returns a pulsed voltage signal to the tilt sensor (C0960) on a BS wire.