D90-4CH Firmware 

 Rev 230518-V1.1  

01. Download the D90-4CH firmware and unzip it.
02. Format a piece of TF memory card.
03. Copy the 'FIRMWARE.img' file to above formatted TF card.
04. Turn off the dash camera. Insert TF card into the slot of the dash camera. Connect dash camera to the power (Dash camera will turn on automatically).
05. The light is blinking during the upgrading. After upgrading finished, turn off the dash camera.
06. Pull out the TF card from dash camera and format the TF card by computer to avoid upgrading again.
Notice: During upgrading, do not disconnect the power to the dash camera.