Operation CHARM: Car repair manuals for everyone.

Principles of Operation

PRINCIPLES OF OPERATION

Interior Lighting System
The instrument cluster illuminates the interior lamps based on input signals from the door ajar switches, headlamp switch and the vehicle security module. The instrument cluster monitors the door ajar switch status on the input circuits for a ground supplied through the ajar switches indicating an open door. The instrument cluster then grounds the battery saver relay and the interior lamp relay control circuits in order to energize the battery saver relay and the interior lamp relay. When the relays are energized, voltage is supplied to the interior lamp circuits.

Illuminated Entry
Illuminated entry is activated when the remote keyless entry transmitter provides a signal to the vehicle security module. The vehicle security module provides a signal to alert the instrument cluster to illuminate the interior lamps. The interior lamps will remain illuminated for a period of up to 25 seconds after all doors are closed or until the ignition is switched from the OFF position.

Demand Lighting
The battery saver relay provides power to the demand lamps. The demand lamp switch, which when activated provide power to the selected demand lamp. The demand lamps are energized anytime the instrument cluster is awake.

Battery Saver
The battery saver is activated when the ignition switch is in the OFF position. The instrument cluster provides a ground circuit for the battery saver relay. The battery saver relay provides power to each demand lamp. The battery saver relay remains energized until a predetermined time-out has elapsed and the instrument cluster deactivates the battery saver relay.