What does 'Smart Key Not Present' mean?

[DelBentley]

Smart Key Not Present may indicate that the key is out of range or the battery is dead, causing the vehicle system to fail to detect the key signal. Below is relevant information about smart keys: 1. Introduction to Smart Keys: A smart key is a device that uses infrared signals to unlock one or two doors, the trunk, and fuel filler cap, and can also control the car's windows and sunroof. 2. Principle of Smart Keys: Smart keys can be divided into two systems: entry system and start system. However, most keyless entry systems include the start function, with only a few models having the entry function alone. The smart entry system utilizes the most advanced RFID (Radio Frequency Identification) technology.