Tilt Sensor: Function

WARNING: This page is about a different car, the 2006 Saab 9-5. However, it is still accessible from the selected car via links, so may be relevant.

When the anti-theft alarm is armed, the tilt sensor is activated when it receives power supply +12V from the control module to pin 1. When the tilt sensor receives the power supply, the sensor confirms this by returning a unique code for the sensor concerned. If there is a fault on the sensor, TWICE is informed by a specific code from the sensor.

If the car is interfered with, e.g. if it is lifted, the sensor will detect this and process the information to decide whether to set off the alarm or not. If the alarm is to be set off, pin 19 on TWICE will be grounded via pin 4 on the sensor.

Once the car key has been removed from the ignition switch, the tilt sensor can be manually disconnected with the CLEAR button. Information that it has been disconnected is sent on the bus and is read by TWICE, which deactivates the sensor.