2012 GMC Sierra Owner's Manual - Page 178

5-40 Instruments and Controls when you begin driving, the brake system needs service as soon as possible. See your dealer. As soon as it is safe to do so, carefully pull your vehicle over to the side of the road and turn the ignition off. Check the wiring connection to the trailer and turn the ignition back on. If this message still displays, either your vehicle or the trailer needs service. See your dealer. See "Integrated Trailer Brake Control System" under Towing Equipment on page 9‑94 for more information. SERVICE BATTERY CHARGING SYSTEM On some vehicles, this message displays if there is a problem with the battery charging system. Under certain conditions, the charging system light may also turn on in the instrument panel cluster. See Charging System Light on page 5‑22. Driving with this problem could drain the battery. Turn off all unnecessary accessories. Have the electrical system checked as soon as possible. See your dealer. SERVICE BRAKES SOON On some vehicles, this message displays if there is a problem with the brake system. If this message appears, stop as soon as possible and turn off the vehicle. Restart the vehicle and check for the message on the DIC display. If the message is still displayed or appears again when you begin driving, the brake system needs service. See your dealer. Door Ajar Messages DRIVER DOOR OPEN This message displays and a chime may sound if the driver door is not fully closed and the vehicle is shifted out of P (Park). Stop and turn off the vehicle, check the door for obstructions, and close the door again. Check to see if the message still appears on the DIC. Brake System Messages SERVICE BRAKE SYSTEM This message displays along with the brake system warning light if there is a problem with the brake system. See Brake System Warning Light on page 5‑25. If this message appears, stop as soon as possible and turn off the vehicle. Restart the vehicle and check for the message on the DIC display. If the message is still displayed or appears again SERVICE TRAILER BRAKE SYSTEM On vehicles with the Integrated Trailer Brake Control (ITBC) system, this message displays and a chime may sound when there is a problem with the ITBC system. When this message displays, power is no longer available to the trailer brakes.