2008 Nissan Altima Owner's Manual - Page 237

If the battery of the vehicle is discharged, the push-button ignition switch cannot be turned from the LOCK position. Some indicators and warnings for operation are displayed on the vehicle information display. See "Vehicle information display" in the "Instruments and controls" section. ON (Normal operating position): This position turns on the ignition system and electrical accessories. CAUTION Do not leave the vehicle with the ignition switch in ACC or ON positions when the engine is not running for an extended period. This can discharge the battery. PUSH-BUTTON IGNITION SWITCH POSITIONS LOCK (Normal parking position): The ignition switch can only be locked in this position. The ignition switch will be unlocked when it is pushed to the ACC position while carrying the Intelligent Key or with the Intelligent Key inserted in the port. The ignition switch will lock when any door is opened or closed with the ignition switched off. OFF: The ignition switch is in the off position when the engine is turned off using the ignition switch. No lights will illuminate on the ignition switch. ACC (Accessories): This position activates electrical accessories such as the radio, when the engine is not running. INTELLIGENT KEY BATTERY DISCHARGE WSD0232 If the battery of the Intelligent Key is almost discharged, the guide light A of the Intelligent Key port blinks and the indicator appears on the vehicle information display. See "Vehicle information display" in the "Instruments and controls" section. In this case, inserting the Intelligent Key into the port B allows you to start the engine. Make sure the Intelligent Key is placed in the correct direction: The front side faces upward and the key ring side faces backward as illustrated. Starting and driving 5-7