2007 GMC Savana Van Owner's Manual - Page 174

See Passenger Sensing System on page 89 for more on this, including important safety information. If, after several seconds, all status indicator lights remain on, or if there are no lights at all, there may be a problem with the lights or the passenger sensing system. See your dealer for service. Charging System Light This light should come on briefly when you turn on the ignition, before starting the engine, as a check to show you it is working. After the engine starts, the light should go out. If it stays on or comes on while you are driving, you may have a problem with your charging system. It could indicate a problem with the generator drive belt, or some other charging system problem. Have it checked right away. Driving while this light is on could drain your battery. If you must drive a short distance with this light on, it helps to turn off all your accessories, such as the radio and air conditioner. {CAUTION: If the off indicator and the airbag readiness light ever come on together, it means that something may be wrong with the airbag system. If this ever happens, have the vehicle serviced promptly, because an adult-size person sitting in the right front passenger seat may not have the protection of the frontal airbag. See Airbag Readiness Light on page 169. 174