2010 Cadillac CTS Owner's Manual - Page 182

5-6 Lighting Lighting Features Entry Lighting The entry lighting system turns on the reading and dome lamps and the backlighting to the exterior lamp control, when a door is opened or if the transmitter unlock button is pressed. If activated by the transmitter, the lighting stays on for about 25 seconds. The entry lighting system uses the light sensor on the instrument panel; so it must be dark outside in order for the lamps to turn on. The lamps turn off about 25 seconds after the last door is closed. They dim then turn off if the ignition key is turned to ON/RUN. They immediately turn off if the power locks are used. Parade Dimming This feature does not let the instrument panel backlight dim during daylight hours while the key is in the ignition and the headlamps are on. Parade dimming automatically works with the light sensor, located on top of the dashboard. If it is dark enough outside and the parking lamps are on, the backlight on the instrument panel can be adjusted by turning the instrument panel brightness knob clockwise or counterclockwise to brighten or dim the lighting. See Instrument Panel Illumination Control on page 5‑5. Battery Load Management The vehicle has Electric Power Management (EPM) that estimates the battery's temperature and state of charge. It then adjusts the voltage for best performance and extended life of the battery. When the battery's state of charge is low, the voltage is raised slightly to quickly bring the charge back up. When the state of charge is high, the voltage is lowered slightly to prevent overcharging. If the vehicle has a voltmeter gage or a voltage display on the Driver Information Center (DIC), you may see the voltage move up or down. This is normal. If there is a problem, an alert will be displayed. The battery can be discharged at idle if the electrical loads are very high. This is true for all vehicles.