2011 Chevrolet Tahoe Owner's Manual - Page 214

6-10 Lighting EPM works to prevent excessive discharge of the battery. It does this by balancing the generator's output and the vehicle's electrical needs. It can increase engine idle speed to generate more power, whenever needed. It can temporarily reduce the power demands of some accessories. Normally, these actions occur in steps or levels, without being noticeable. In rare cases at the highest levels of corrective action, this action may be noticeable to the driver. If so, a Driver Information Center (DIC) message might be displayed, such as BATTERY LOW START VEHICLE . If this message displays, it is recommended that the driver reduce the electrical loads as much as possible and restart the vehicle. See Battery Voltage and Charging Messages on page 5‑37. Battery Power Protection This feature shuts off the dome, and reading lamps if they are left on for more than 10 minutes when the ignition is off. This will keep the battery from running down.