Control Module, Theft Protection: General

WARNING: This page is about a different car, the 2002 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.

The theft protection functions for the alarm and immobilizer are part of TWICE and are controlled by the system control module. See TWICE for further information.

The main task of the control module for the anti-theft alarm function is to monitor the status of the sensors continuously as a central unit when the alarm is armed, trip an alarm via the siren and/or direction indicators if a break-in occurs and prevent the car from starting via the immobilizer.

The control module contains a processor in which a fixed control program is stored in a PROM (Programmable Read Only Memory). As different markets have special requirements for the function of anti-theft alarms, this can be programmed to suit the market concerned. There are also several options for changing the function depending on the customer's preferences.

The module is programmed using Tech 2 and the information is stored in an EEPROM (Electrically Erasable PROM). The previous programming is deleted when a new program is entered. The stored programming is retained in the event of a power failure.