NMEA 2000 Gateway Troubleshooting Guide

Below are common troubleshooting tips for issues with your Mercury Marine NMEA 2000 Gateway device. 

The indicator lights on a Mercury Marine NMEA 2000 Gateway can help identify communication, connection, and power problems between the engine CAN bus and the boat’s NMEA 2000 network.

Use the chart below to compare the status of the CAN and NMEA lights. Before replacing the gateway, inspect the harness connections, confirm power is present, and verify that the connected chartplotter is running current software.

Gateway Module Light Functions (Engine and Helm)

Use the CAN and NMEA indicator lights on the gateway module to help identify connection, power, or communication problems.

Gateway Light Function / Troubleshooting
CAN NMEA
On On
  1. The gateway module is connected to both a functioning CAN bus and NMEA 2000 bus. Data will be transferred as required.
  2. Update or verify the chartplotter software. Consult the chartplotter manufacturer’s website.
  3. If data is not being transferred, the NMEA 2000 bus device IDs may not be approved and may be blocked. Contact Mercury Marine service for the helm gateway (autopilot) device approval list.
Off On
  1. The gateway module is connected to the NMEA 2000 bus and is receiving data on the bus.
  2. The gateway module is not connected to the CAN bus. Check the CAN bus connections.
  3. Power is not present at the CAN 10-pin harness connector.
On Off
  1. The gateway module is connected to the CAN bus and is receiving data on the bus.
  2. The gateway module is not connected to the NMEA 2000 bus. Check the NMEA 2000 bus connections.
  3. Power is not present at the NMEA 2000 harness connector.
Off Off
  1. The gateway module is not connected to either the NMEA 2000 bus or CAN bus. Check the connections on both sides. If the connections are good, the gateway module may require replacement.
  2. Power is not present at the gateway CAN 10-pin harness connector or at the NMEA 2000 harness connector.
Blink
Connected to NMEA 2000 only 		The circuit has an intermittent connection. Check the NMEA 2000 harness and connections.
Blink
Connected to NMEA 0183 		The NMEA light will blink during normal operation. Refer to the CAN light status above for additional troubleshooting.
Important: A gateway that is not transferring engine data does not necessarily require replacement. Loss of power, loose connections, network problems, outdated chartplotter software, or an unsupported device ID can produce similar symptoms.