Theft alarm system – circuit operation

THEFT ALARM SYSTEM – CIRCUIT OPERATION

Inertia Switch

An inertia switch is incorporated in the Theft Alarm Unit (Z163). If ignition is on and the vehicle receives an impact sufficient to activate the inertia switch, the unit will signal to unlock central locking actuators and flash hazard lights. Central locking will remain disabled for a period of 0 to 5 minutes. To reset, turn ignition off and then on after the time period has elapsed.

Alarm Sensor (X213)

The sensor operates by emitting an air pressure carrier wave and receiving the wave back. Any disturbace within the vehicle which disturbs the wave will be detected, triggering the alarm. When the volumetric sensor is activated, it monitors movement within the vehicle for 15 seconds before detecting and responding to intrusions. If the sensor detects movement within the vehicle, it delays arming until a 15 seconds quiet period has elapsed. If continuous movement is detected, the alarm will not arm volumetrically.

ENGINE IMMOBILISATION FUNCTION (Not on all vehicles!)

The engine will be immobilised whenever the theft alarm is armed or the Theft Alarm Unit (Z163) enters the Passive Immobilisation mode (regardless of whether or not the theft alarm is armed). There are two methods of Engine Immobilisation featured: 1. Electronic Engine Immobilisation (used on MFI-T16 and 300 Tdi with EDC engines) 2. Remote “Smart Spider” Immobilisation (used on MFI-V8 and 300 Tdi without EDC engines) The vehicle may only be mobilised by using the handset or entering the correct EKA code.

Electronic Engine Immobilisation (MFI-V8) (300 Tdi with EDC)

The electronic engine immobilisation is controlled jointly by the engine management system’s Electronic Control Module (ECM) (Z132) and the Theft Alarm Unit (Z163). When the Theft Alarm Unit (Z163) immobilises the vehicle, it sends a signal to the ECM. The ECM then immobilises the engine management system until a mobilise signal is received from the Theft Alarm Unit (Z163).

Remote “Smart Spider ” Immobilisation (MFI-V8) (300 Tdi without EDC)

The Remote “Smart Spider” Immobilisation is controlled jointly by the Engine Immobilisation Control Unit (Spider) (Z271) and the Theft Alarm Unit (Z163). When the Theft Alarm Unit (Z163) immobilises the vehicle, it sends a signal to the Engine Immobilisation Control Unit (Spider) (Z271). The “Spider” then interrupts the starter circuit, fuel pump circuit, and Ignition coil circuit for MFI-V8 engines, or the starter circuit and the fuel pump shutoff solenoid circuit for 300 Tdi without EDC engines. These circuits will remain interrupted until the “Spider” receives a mobilise signal from the Theft Alarm Unit (Z163).