Operation CHARM: Car repair manuals for everyone.
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Basic Function Of The Anti-Theft Alarm System






Control
The "nerve center" of the anti-theft alarm system is a main unit (electronic control module) which controls all system functions.

Sensing
The anti-theft alarm incorporates a number of sensors which are connected to the alarm's electronic control module via the car's wiring harness. These sense an attempt to break into the car and send a signal to the alarm's electronic control module.

Alarm signal
When the alarm is set off, this is made apparent with sound by the alarm horn sounding and/or light by all the direction indicators flashing.

3-circuit breaking, anti-theft alarm
Incorporated in the electronic control module for anti-theft alarms without VSS is a "3-circuit breaking" function which is activated at the same time as the alarm is set off. This prevents the engine from being started by blocking the car's ignition system, fuel supply and engine management system.

Immobilizing (anti-theft alarm with VSS
Incorporated in anti-theft alarms with VSS is an "immobilizing" function which, via the car's engine management system, always prevents unauthorized persons from starting the car

Operation
Operation, that is to say arming and disarming the anti-theft alarm, is accomplished by remote control. The anti-theft alarm without VSS can also be operated by the car key (the car key function is programmable).

Alarm status
There is an LED in the car to show the status of the alarm. This flashes with different frequencies or is lit continuously depending on the situation.

Programming/diagnostics
The Intelligent Saab Tester (ISAT) scan tool is used for programming and scan tool diagnostics on the theft alarm.