Combination Switch: Description and Operation

TURN SIGNAL SYSTEM
The multi-function switch is a resistive MUX switch that is monitored by the Instrument Cluster. The turn signals are actuated with the lever on Multi-Function Switch. The signals are automatically turned off by a canceling cam (two lobes molded to the back of the clock spring mechanism). The cam comes in contact with the cancel actuator on the turn signal (multi-function) switch assembly. Either camlobe, pushing on the cancel actuator, returns the switch to the OFF position.

The Instrument Cluster monitors the multiplexed multifunction switch. In a turning event the Instrument Cluster senses a change in the turn signal lever and illuminates the appropriate turn signal indicator. At the same time, the Instrument Cluster will send a J1850 message on the PCI bus to the Front Control Module (FCM). The FCM will respond by activating the appropriate relay in the Power Distribution Center.

A chime will sound after the turn is completed if vehicle has traveled a distance of approximately 1.0 mile and a speed of 15 mph, with the turn signal ON.