Horn Relay
WARNING: This page is about a different car, the 2004 Dodge Pickup and 2004 Dodge Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The Horn Relay, which is internal to the IPM, is controlled by the FCM through PCI bus messages from the instrument cluster. These bus messages will be sent when either the horn switch is pressed which is hard wired to the instrument cluster, panic mode is requested from the RKE or for vehicle theft security reasons (if equipped). The relay control circuit is continuously monitored for malfunctions that the FCM will report as DTCs.