Answer: To protect the device electronics from undervoltage and resulting malfunction of function modules, the ZENEC mainboard and the MCU constantly measures the power supply voltage via sensor, to to trigger a shut-down (and reboot) if the supply voltage drops below 9 V. The automatic sense process avoids faults on the device operation and incomplete loading of software parameters. This is a device self protection mechanism and not a defect. If the device does a frequent reboot after engine start, it is recommended to see your car dealer for an inspection of the battery condition, and or if wires and contacts are corroded and, which would cause the supply voltage to drop below 9V.