Hazard Warning Lamps: Description and Operation

HAZARD WARNING LAMPS
The hazard warning system includes the EMIC, the FCM and the hazard switch on the SCM on the steering column. The FCM monitors a hard wired input from the hazard switch to determine the status of the hazard switch. The FCM responds to this input by controlling a battery voltage output and the flash rate for each of the right and left turn signal lamps. The FCM then sends the appropriate electronic hazard switch status messages to the EMIC over the CAN data bus to control the illumination and flash rate of the right and left turn signal indicators, as well as to control the click rate of an electromechanical relay soldered onto the EMIC electronic circuit board that emulates the sound emitted by a conventional hazard warning flasher. Although the hazard switch is mounted to the SCM, the hazard switch circuits only pass through the SCM. The SCM has no control over and does not monitor the hazard switch output.