Technical description: Horn

Fig 1: Identifying Horn Functional Diagram

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Fig 2: Circuit Diagram - Horn

Courtesy of SAAB-SCANIA OF AMERICA, INC.

The SID unit obtains information on the status of the horn switch from the steering wheel control.

Relay (68) for the horn is powered with +30 via fuse 10 in the dashboard fuse box (22a). When the steering wheel switch for the horn is activated, SID will ground pin 17 to activate the relay and sound the horn.

The horn is also used to acknowledge "TSL" locking of the car. The SID unit obtains information via the bus from TWICE to activate the horn.