You will receive this error if your vehicle’s PCM reads less than 11.5 volts from the battery of your vehicle.
To resolve this issue, ensure the voltage is at least 12.0v with the key on. You can read this voltage in the “Device Info” screen, under “vbatt”
If your vehicle is not above the minimum voltage, we recommend connecting your vehicle to a battery charger. Test your voltage again, if your "vbatt" is staying above 12.1V then tune your vehicle with the battery charger still on the vehicle.
If your vehicle still does not stay above 12.1V with the key on and the battery charger connected, you will need to investigate the issue with the vehicle before proceeding to tune.