JimH wrote:
"I can't offer any advice regarding a Yamaha engine and connecting it to a NMEA-2000 network. There seems to be some peculiarities associated with where you connect to the engine data depending on what type of Yamaha-brand instrumentation you already have. If you solve that puzzle and work out the various dependencies, as I am sure you will be successful at doing, a separate discussion on the topic "Connecting Yamaha engine to NMEA-2000 Network" would be very welcome. I don't understand what the mystery is about it, and I have not seen a good explanation of the why's and the wherefore's."
I accept this kind invitation, or perhaps it should be considered a challenge. There are indeed some peculiarities associated with connecting a Yamaha engine to an NMEA 2000 network; one can confirm this by performing Google searches on The Hull Truth Boating Forum (at https://thehulltruth.com), a boating and fishing discussion board that is said to be the largest of its kind, using the phrase “Connecting _________ engine to NMEA 2000 network”, filling in the blank with Mercury, Yamaha, or Honda. “Mercury” yielded about 1,000 results, while “Yamaha”, a brand with an approximately equal market share, gave three times that number. The search using “Honda”, a brand that probably has about one third the outboard motor market share of Mercury, yielded about 1/3 as many results. (Suzuki seems to be an outlier here - their engines require a proprietary adapter to output NMEA 2000 data, as does Mercury, but their system has led to more online discussions than any other brand when accounting for the (presumed) smaller numbers of engines sold. Many of the postings indicate that Suzuki has had problems with the firmware in their interface adapter.) I believe there is an explanation for these findings, but it might be best to start with a little background.
My first car, a 1962 Ford Falcon, had only one electronic device: a vacuum tube AM radio. Nowadays, the average automobile has 30 to 50 electronic control units (ECUs), with some luxury cars having as many as 100. As more complex automotive control systems were being developed, it became apparent that point-to-point wiring systems were not practical, so a German automotive engineering firm (Bosch) developed a communication protocol called Controlled Area Network (CAN) that greatly reduced the complexity of automotive wiring harnesses. A CAN bus (“bus” here meaning a system that carries electrical signals; it is typically a set of wires) allows ECUs to communicate with each other via a single wire loop without a host computer; it is simple, inexpensive, efficient, and extremely robust. Today, CAN systems have been developed for use in cars, trucks, tractors, buses, ships, planes, EV batteries, medical devices, and machinery. The current maritime CAN was developed by the National Marine Electronics Association (NMEA) in 2000, and the pieces of transmitted data are identified by a Parameter Group Number (PGN). For more details about the NMEA 2000 system, I recommend the excellent reviews to be found here; for a detailed discussion of the relevant connections involved, go here.
There are three other communication protocols of which boaters should be aware: NMEA 0183, an older, simpler, and slower maritime protocol; J1939, a CAN protocol from which NMEA 2000 was derived that was originally developed for heavy-duty vehicles; and Ethernet, a high-speed point-to-point protocol used for video transmission and the Internet. While NMEA 2000 is the most common protocol used in recreational marine equipment, some multifunction displays can communicate via other protocols. One unit I recently examined, a Garmin GPSMAP 943xsv, has connections for NMEA 0183, NMEA 2000, J1939, and Ethernet. Most of this narrative deals with NMEA 2000, but I will touch on some of the other protocols, too.
NMEA 2000 was designed to be a standardized plug-and-play system for connecting marine devices produced by different manufacturers, so why is there is so much discussion about the connection of a Yamaha outboard motor to an NMEA 2000 network? At first glance, the type of engine NMEA interface does not appear to determine the amount of online discussion. Mercury engines can connect to an NMEA 2000 network only by using a proprietary interface adaptor, or “gateway”, while Honda engines directly output NMEA 2000 information that can be accessed without any proprietary interface, and the PGNs sent by Honda's ECU are publicly available. As noted above, neither system has generated much online discussion. In contrast, Yamaha’s system is not so straightforward. Here is something I pulled from the Garmin ECHOMAP UHD2 6/7/9 2022 user manual regarding the display of engine gauge data on the ECHOMAP from Yamaha engines:
"For the best experience monitoring and controlling your compatible Yamaha engine or motor using this chartplotter, you must connect your engine or motor to the chartplotter using the appropriate interface adapter. If needed, contact your Yamaha dealer for more information."
Aside from the appearance of a proprietary screen format, the ECHOMAP manual does not indicate how one’s experience will be improved by using the Yamaha gateway.
Here is another revealing statement taken from the online Garmin Support Center (at https://support.garmin.com/en-US/?faq=0 ... U4vCHDgiA6):
“While some Yamaha engines may be able to integrate directly via NMEA 2000 without the use of a gateway, the installation itself is not something Garmin Product Support can assist with. It is possible that data displayed may be correct, provided the NMEA 2000 PGNs are supported by any networked chartplotters. For more information on supported NMEA 2000 PGNs, consult the Owner's Manual for the chartplotter. For information on how to accomplish this sort of install, consult with a Yamaha dealer.”
I suspect that much of the online discussion about NMEA 2000 connections to Yamaha engines is generated by owners who are trying to connect their chartplotters directly via a standard NMEA 2000 network without using Yamaha’s interface adapter (which currently sells for about $450 at SIM Yamaha). I have encountered eight different ways to get data from a Yamaha outboard motor to a Garmin chartplotter, but neither the Yamaha owner’s manual nor the service manual for the Yamaha F-70 mention NMEA 2000 connections, and the Yamaha rigging manual has a few diagrams with little explanation. This lack of information and support from Garmin and Yamaha has left some owners who work on their own boats struggling just to find the Yamaha NMEA plug, and I think it has contributed to the proliferation of online information and advice that is well-meaning but not always accurate. Here is one bit of misinformation from the continuousWave forum:
"Almost all modern outboard engines are certified for connection to a NMEA-2000 network. The only exceptions are Mercury Marine outboard engines." (from https://continuouswave.com/whaler/refer ... A2000.html)
If that were true, I probably wouldn’t be posting this narrative. There are no Yamaha engines that are NMEA certified. To my knowledge, Yamaha does not claim that the CAN data coming from their engines comply with NMEA standards. It’s Yamaha data, some of which include NMEA 2000 data. But don’t take my word for it, go to the NMEA website here and type in “Yamaha” to see which of their products is NMEA 2000 certified (only their CL7 display, which is made by Garmin). Of the gasoline-fueled outboard motor manufacturers currently represented in the United States, only Honda engines are NMEA certified (more precisely, it is the Honda engine's ECU that is certified; the engine management module (EMM) for Evinrude ETEC engines was also NMEA 2000 certified.) Please note that products listed as “NMEA compliant” or “NMEA compatible” may not meet the rigorous standards to which NMEA certified products are held. You can find Garmin's view of this matter here.
As if there wasn’t enough confusion about Yamaha NMEA connections, equipment manufacturers seem to have overlooked that the Yamaha F-70 can be connected to an NMEA 2000 system. Take a look at the Navico info (available for download from continuousWave here) on how to connect their devices to Yamaha engines, and you will see that the F-70 is not listed among the Yamaha outboards compatible with NMEA 2000; however, this is an error, as noted on the Yamaha F-70 hot sheet (at https://yamahamarinemedia.com/wp-conten ... tSheet.pdf). I have seen this omission in many other places online, so it is no surprise that some F-70 owners wonder whether their engines can be connected to NMEA 2000 devices.
Please don’t get me wrong; I think Yamaha and Garmin make excellent products, and I own both brands of equipment, but I think their corporate decisions have led to much confusion among owners, hence the “mystery”.
Next: Options for getting data from a Yamaha F70 outboard to a Garmin chartplotter.