Horn System - Operation

OPERATION

The horn system operates on battery current received through fuse 41 and 42 in the Totally Integrated Power Module. The horn system circuit is designed so that the system will remain operational, regardless of the ignition switch position.

On vehicles with an optional EVIC the right EVIC switch is also a LIN bus slave, sharing a LIN input circuit to the CCN (LIN master) with the Steering Control Module (SCM) within the left multifunction switch, which is also a LIN bus slave. Both the right and left EVIC switches also share an IOD feed and a ground feed in common with the SCM.

On vehicles with an EVIC, the right EVIC switch microprocessor is connected to and monitors the outputs of the left EVIC switch. The right EVIC switch also is connected to the horn switch and the remote radio switches through a common sensor signal circuit. The right EVIC switch monitors the horn switch state through a dedicated return circuit and monitors the resistor multiplexed remote radio switches through a second dedicated return circuit. Finally, the right EVIC microprocessor communicates the status of each and every one of these switches to the CCN over the LIN data bus.