AW: To protect the device electronics from under voltage conditions and resulting malfunction of function modules inside the device the ZENEC mainboard and the MCU constantly measure the power supply voltage via sensor, 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 data. This is a device self protection mechanism and not a defect. If the device does reboot after engine start from time to time, it is recommended to see your car dealer for an inspection of the condition of the battery, and or if wires and contacts are corroded to cause supply voltage drop below 9V.