Anti-theft system and immobilizer — general information (Opel Astra G)

1. All the vehicles under consideration are equipped with an engine start failure system (immobilizer). The transmitter module of the system is built into the ignition key and sends a start permission signal to the receiver mounted in the steering column.

2. The anti-theft system of the cars in question is triggered by a transmitter built into the key and includes an audible signal. The system consists of limit switches installed on the doors and hood and ultrasonic sensors installed in the passenger compartment on the central pillars of the body (see photo).

21.2 Anti-theft system
1. Central locking and anti-theft alarm control unit
2. Underhood limit switch
3. LED (inside the hazard warning switch)
4. Ignition switch
5. Ultrasonic sensor
6. Glass break sensor (connecting the rear window heater circuit to the central locking and anti-theft alarm control unit)
7. Switch built into the trunk lid
8. Luggage compartment lighting
9. Driver's door lock drum switch

3. The underhood limit switch is secured with 2 screws near the edge of the hood (see photo).

4. The central lock and anti-theft alarm control unit (ATWS unit) is secured with 2 nuts on the front body pillar. First, you need to remove the cover by unscrewing the screw (see photo).