Can Bus 101

[mkov608]

A recent post inspired me to share what I've learned about Can Bus (or communication networks) on Sea-Doos (see YouTube video link below). The structure of the communications network on Sea-Doos is identical to that in the automotive industry down to the voltage in the Can-hi and Can-low bus circuits. The big difference is a typical car can have over 30 modules on the bus compared to a Sea-Doo which only has 4-5 modules on the bus.

The Can Bus is critical to your Sea-Doo's operation especially with the later model skis which are drive-by-wire. It is important to understand that these network carry digital information (bi-directionally) from one module to another at very low voltages. Water intrusion, corrosion, damaged connectors etc can all play havoc with how your ski operates.

I do not claim to be an expert on Can Bus networks, but hope the video sheds some light on the subject, and gets you in the learning mode. If you are a Can Bus expert, feel free to add your knowledge and experience to the discussion.

Original thread: 2013 RXT 260x do I need new wiring harness and/or ECM

Can Bus Troubleshooting 101

 

[ski-d00]

Very nice video and clearly explained.

The diagnostic cap really isn't necessary for the ski to operate perfectly. Every function will work perfectly if this is unplugged and the only thing I've ever seen it do is throw a code that the cap is unplugged but this code won't even come up on the cluster of the ski and can only be seen on BUDS. I know most terminating resistors are required for proper operation but BRP knew people would leave this unplugged which I've seen tons of them unplugged or the cap is completely gone so they have their system a little different.

 

[mkov608]

Thanks! I just don't like seeing folks get billed for parts the dealership will use to troubleshoot the problem.

Thanks for the information the cap. In a car, you can't remove the terminating resistors, and based on their function, I'm surprised it doesn't cause problems when one is removed.

Bruce came over yesterday with the ski; I was going to post a video on what we found, but some of the files got accidentally deleted. His network had a lot of "hash" in the signal and the square waves were not "square"; the tops of the signal were sloped. The signal got even weirder when I disconnected the iBR connector. I pulled the iBR cable; the socket on the iBR was full of mud, and the harness side was full of water. I cleaned everything up. I only had a 1 volt signal on Can-hi when I was finished, but I did have a nice square wave with reduced hash. We're taking it out in a few minutes for a test ride.

My brother sent this email reply to my video.

"That was short and very informative.

I had thought, with the new ski, that the fire control system (depth charges and torpedoes) would communicate over CAN.

Surprised SeaDoo left out that part."

Tim