Autopilot System: No Device Detected - Troubleshooting and Actions

There can be various reasons why your autopilot display shows the error message "No device detected". Here are some things to check/test:

1. Check that the voltage to the ACU is appropriate while the ACU is on and driving the unit (i.e., under load). If the voltage drops to 11V or less, the ACU may reset and show this message. Additionally, if the ACU does not have main power, you will see this error.
   
   
   
   
2. Check the STng cables from the ACU to the STng system, and it is also worth checking the EV-1 cables. If communication is lost between the EV-1 and the ACU, it will alarm.
   
   
   
   
3. Check the connection cables from the drive motor to the ACU. If the ACU does not detect the back EMF from the motor, it will alarm "no device detected".
   
   
   
   
4. If this system is Drive by Wire (DBW), there may be an issue with the interface between the EV-2 (or ECI-100) and the engine interface. Check the bus connections.