• Check if the system has been turned on. Press button to turn on the unit.
• Check if the car engine is on. Start the car engine to provide the necessary power to the system.
• Press RESET button to reset the system.
• Check if the fuse is burnt. Replace the fuse if it is burnt. 

If the above does not work, check the connections of the system to the car. (Refer to the user manual for detailed connections.)