2010 GMC Sierra 1500 Crew Cab Owner's Manual - Page 241

A high electrical load occurs when several of the following are on, such as: headlamps, high beams, fog lamps, rear window defogger, climate control fan at high speed, heated seats, engine cooling fans, trailer loads, and loads plugged into accessory power outlets. 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 SAVER ACTIVE, BATTERY VOLTAGE LOW, or LOW BATTERY. If this message is displayed, it is recommended that the driver reduce the electrical loads as much as possible. See DIC Warnings and Messages on page 4‑66. Battery Run-Down Protection This feature shuts off the dome and reading lamps, if they are left on for more than 10 minutes after the ignition is turned off. The cargo lamp shuts off after 20 minutes. This prevents the battery from running down. Accessory Power Outlet(s) Accessory power outlets can be used to connect auxiliary electrical equipment, such as a cellular telephone. The vehicle may have two accessory power outlets located below the climate control system, or may have one accessory power outlet and one cigarette lighter. The cigarette lighter is designed to fit only in the receptacle closest to the driver. There may be another accessory power outlet in the rear cargo area. If the vehicle has a floor console, there is an accessory power outlet inside the storage bin and one on the rear of the floor console. 4-17