2012 GMC Acadia Owner's Manual - Page 133

Instruments and Controls If the light stays on, or comes on while driving, there may be a problem with the electrical charging system. Have it checked by your dealer. Driving while this light is on could drain the battery. When this light comes on, the Driver Information Center (DIC) also displays the SERVICE BATTERY CHARGING SYSTEM message. See Vehicle Messages on page 5‑35 for more information. If a short distance must be driven with the light on, be sure to turn off all accessories, such as the radio and air conditioner. If the malfunction indicator lamp comes on and stays on while the engine is running, this indicates that there is an OBD II problem and service is required. Malfunctions often are indicated by the system before any problem is apparent. Being aware of the light can prevent more serious damage to the vehicle. This system assists the service technician in correctly diagnosing any malfunction. comes on when the vehicle is placed in ON/RUN, as a check to show it is working. If it does not, have the vehicle serviced by your dealer. See Ignition Positions on page 9‑15 for more information. 5-17 Notice: If the vehicle is continually driven with this light on, the emission controls might not work as well, the vehicle fuel economy might not be as good, and the engine might not run as smoothly. This could lead to costly repairs that might not be covered by the vehicle warranty. Notice: Modifications made to the engine, transmission, exhaust, intake, or fuel system of the vehicle or the replacement of the original tires with other than those of the same Tire Performance Criteria (TPC) can affect the vehicle's emission controls and can cause this light to come on. Modifications to these systems could lead to costly repairs not covered by the vehicle warranty. This could also result in a failure to pass a required Emission Inspection/ Maintenance test. See Accessories and Modifications on page 10‑3. Malfunction Indicator Lamp A computer system called OBD II (On-Board Diagnostics-Second Generation) monitors the operation of the vehicle to ensure emissions are at acceptable levels, to produce a cleaner environment. This light