Technical description: Horn
WARNING: This page is about a different car, the 2001 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
Two horns of the trumpet type are located behind the grille under the radiator cross-member. The horn switch is located in the centre of the steering wheel.
The horns are tuned to different frequencies. The horn marked H is high frequency and the one marked L is low frequency.
The horn switch (336b) is connected to SID pins 3 and 18. When the horn switch is pressed, the SID grounds pin 17 and the relay (68) operates. Power +30 is fed from fuse 10 through the relay (68) to both horns (40).
The horn is also used for confirmation of "TSL"-locking (Theft Security Lock) of the car. The SID unit receives information via the bus from TWICE and the horn is activated.