Lowrance HDS Engine Data Lost — NMEA 2000 Fix Guide

What Does This Error Mean?

'Engine Data Lost' means the chartplotter can no longer receive engine data over the NMEA 2000 network.
Either the engine gateway has failed, the network has a wiring fault, or the engine is off.
Check the network terminator and power.
Most engine data losses are network-side — backbone wiring issues or terminator problems.
Engine itself usually still works fine.

Affected Models

Lowrance HDS Live
Lowrance HDS Carbon
Lowrance Elite FS
Lowrance HDS Pro

Common Causes

Engine off (data only flows when engine running)
NMEA 2000 backbone disconnected at a T-fitting
Network terminator missing or failed
Engine NMEA 2000 gateway failed
Network power supply tripped or disconnected

How to Fix It

Check whether the engine is running.

NMEA 2000 engine data only flows when the engine is running.
If you've shut down the engine, the chartplotter's last reading just before shutdown stays displayed for a moment, then 'Engine Data Lost' appears.
Start the engine and the data resumes within seconds.
Open the network status.

On the HDS, open Settings → Network → NMEA 2000 → Sources.
Check the list of detected sources.
If the engine is missing, the network has lost the engine gateway.
If the engine is listed but data is stale, the gateway is connected but not transmitting.
Inspect the network backbone.

Find the NMEA 2000 backbone cable in your boat.
Trace it to confirm all T-fittings are secure.
Loose T-fittings are the most common network issue.
Push each connector firmly until it clicks.
Don't overtighten — these are designed for hand-tight.
Check the network terminators.

NMEA 2000 needs a terminator at each end of the backbone (a small resistor in a connector).
If a terminator is missing or has corroded, the network becomes unreliable.
Confirm both terminators are in place and connected.
Replacements are 10-20 USD.
Check network power.

NMEA 2000 needs 12V power on the backbone.
The power tap is usually a small T-fitting with red and black wires going to the boat's electrical panel.
Confirm the breaker is on and voltage is present.
If power is missing, the whole network goes silent and engine data is lost.

Frequently Asked Questions

Will the chartplotter still work without engine data?

Yes — GPS, charts, sonar, and waypoint navigation all work independently of engine data.
You'll just lose engine RPM, fuel rate, fuel level, and engine alarms displayed on the chartplotter.
For day fishing this is workable; for long trips you'll want engine data restored.

Can I diagnose NMEA 2000 issues with the chartplotter?

Some.
The HDS shows source list and basic status.
For deeper diagnostics, a NMEA 2000 analyzer (200-500 USD) shows traffic and helps find faulty devices.
For most issues, the basic 'check terminators, check power, check connectors' workflow finds the problem.