Acoustic indicator
When a message is displayed in SID (541) it is indicated with an acoustic signal in the dashboard speakers. If several messages are displayed then only the first message is indicated with an acoustic signal.
ICM (736) is a control unit for warning and indicator sounds, which means that it manages the prioritizing and activates EHU (353).
ICM receives a bus message to generate an acoustic signal and in turn transmits a bus message on the O-bus requesting an acoustic signal in the loudspeakers. EHU (the radio main unit) receives the bus message and sends an acoustic signal to the front speakers.
An EHU (353) is also fitted in cars without audio system in order to generate warning and indicator sounds.