Communication issues with 8.1’s
- Thread starter Three Seasons
- Start date
Hey guys - give it up on the CAN (Smartcraft) networks (there are three Smartcraft data systems). These systems have nothing to do with the functional operation of the boat and engines. These data systems only read and display information. They "control" nothing.
Also, the idea of a sequence of starting and shutting down is for not.
There are three areas to focus - Ignition power, ECM unswitched power, and grounding.
Intermittent and unpredictable loss of electrical power that causes issues with the boat's performance is typically loss of one of these three electrical systems. Switching, connectors, and a bad wire crimp/broken wire inside of the connector are usually the culprits. Getting this sorted out is important because as any sparking in the ignition circuit sends huge voltage spikes to the ECM and can fail that incredibly expensive device.
Also, the idea of a sequence of starting and shutting down is for not.
There are three areas to focus - Ignition power, ECM unswitched power, and grounding.
Intermittent and unpredictable loss of electrical power that causes issues with the boat's performance is typically loss of one of these three electrical systems. Switching, connectors, and a bad wire crimp/broken wire inside of the connector are usually the culprits. Getting this sorted out is important because as any sparking in the ignition circuit sends huge voltage spikes to the ECM and can fail that incredibly expensive device.
Korkie
Active Member
- Feb 2, 2016
- 1,331
- Boat Info
- 2006 340 Sundancer, Garmin 7610, xHD 24 Radar, VV703, SeaStar Hydraulic Steer, Shadow Drive AP
- Engines
- Mercruiser 496 Mags
Bravo III Drives
I understand what you are saying, although after we cleaned all of the grounding bolts, all positive connections on both motors, changed out both fuses at the starter, checked all the coil packs, changed plugs/wires, changed circuit breakers and key switches on the electrical panel, changed out the starter switches at the helm, ran numerous computer checks while this was occurring to reveal nothing, checked fuel pressures that were unchanged when it was occurring, the list goes on. It wasn't until we found the spliced can buss cable (from PO) when doing the VV and steering upgrade and replaced both can bus cables and the VV that the problem stopped. Coincidence? Maybe? But after 4 years of chasing this ghost I will take it.
Thank you for continuing help with this… It’s literally keeping me up at night. It’s so random but getting worse. Ran the boat Saturday morning and only did it once, Monday morning did it 20 times in 30 minutes.
The Blue and the White wires are CAN P. The Red and Black wires are power. That power is shared through the ignition circuit. What I'm saying is the Smartcraft CAN network will not impact the boat's operational characteristics. You will lose data and that's it.
Understand, but willing to try anything. Captlori received the cables last week I’m waiting to hear the results.
Tripsdad
Well-Known Member
So after cleaning all the grounds, checking all wires and connections, disconnecting the Dash/ignition and running the motor from a laptop and changing the crank position sensor my mechanics swapped the ECM’s. I ran the boat that weekend and still had the same issue and according to my gauges it was still happening on the starboard motor so I thought we ruled out the ECM. That was in Sept and my mechanics sent a download to Merc with nothing noted. This past week before we pulled the boat they sent another down load and swapped out the PCM’s but this time they stayed in the bilge and saw the issue move to the port motor. I met with the mechanics today and apparently the PCM / ECM’s are programmed for port or starboard so even though it looked like it was still the starboard motor continuing to have the issue it actually moved to the starboard with the PCM. The other interesting point is that before they swapped the PCM my starboard motor would beep twice and the port once prior to start up but once they swapped the PCM’s the port had two beeps and the starboard back to one. They are planning to speak to Merc again this week but it sounds like they finally found something that seems to make sense. I will keep updating as we find out more.
Thank you so much for your detailed update, I was worried this thread was dead and our problems continued. Our boat is stored for the season, the day we pulled it I had one beep on starboard 6 min after start up and no issues for 45 min to ramp. 1 hour waiting for pull-out I restarted and both tach’s and both motors were acting up with multiple beeps and RPM surges. We have done ALL of the above with the exception of PCM/ECM swapping. I look forward to your update. I was thinking about sending both PCM/ECM’s to a recommended company for evaluation and reprogramming but I need to find a good one.
About 10 years ago I had a friend with an 8.1 that would beep every 10 seconds, they determined (guessed) the ECM was damaged from a lightning strike. The ECM had no codes. ECM was replaced with a new one for $2200 covered by insurance and problem was solved. This was a single engine and as I recall had no RPM surge.
I (we) look forward to your next update.
All the Best,
About 10 years ago I had a friend with an 8.1 that would beep every 10 seconds, they determined (guessed) the ECM was damaged from a lightning strike. The ECM had no codes. ECM was replaced with a new one for $2200 covered by insurance and problem was solved. This was a single engine and as I recall had no RPM surge.
I (we) look forward to your next update.
All the Best,
Tripsdad
Well-Known Member
We hauled the boat last Friday and it's winterized and shrink wrapped but they are continuing to work with Mercury so we can hopefully have a plan before spring. Stay tuned…
Spring is approaching and I’m yet to figure this out. I posted these you tubes for help understanding my issues. If you have nothing to do read this string started by me and added to by frustrated others. This all started August of ‘21 and only effected the starboard side one time at start up. Now it can be S or Port and sometimes both at the same time as video’d. I drove the boat to be stored last fall it never did it then when I restated to drive onto trailer it did it 4 times in 10 minutes both sides. Just to note there is a brief RPM surge when it beeps and the tachs drop. Sometimes the power never returns to the dash but the motors run fine. Driving me crazy!!! Thanks for watching
Korkie
Active Member
- Feb 2, 2016
- 1,331
- Boat Info
- 2006 340 Sundancer, Garmin 7610, xHD 24 Radar, VV703, SeaStar Hydraulic Steer, Shadow Drive AP
- Engines
- Mercruiser 496 Mags
Bravo III Drives
Captlori - Just had another thought after watching your videos. I think I have this right, but may not. The analog gauges get their information from the digital information from the SmartCraft. There are junction boxes under the helm (behind the dash panel). I am wondering if that is where you problem may lie. It could be that someone disconnected them and didn't quite reconnect them properly (wrong cable into wrong junction box). Not sure if you have looked at this yet, but certainly makes sense. Or maybe one or more of them are worn out, dirty, etc and just not making good contact? Ours did exactly what yours was doing on the video. Once we found the spliced cable with the but connectors, we were sure that was it. Although, we also removed the entire SC5000 and upgraded to a VV703. Just some thoughts and maybe another place to investigate. Best of Luck.
Tripsdad
Well-Known Member
My mechanic brought the boat into the shop this week and they called me today to confirm the ECM needs to be replaced. An expensive fix if that what it is but will be happy if it resolves the issue.
@Three Seasons - My issue is a little bit different than yours since it only affects one motor but I'm curious how your friend determined the ECM was struck by lightening to get insurance to cover it.
I told them to order the new ECM (~$3K) and I'll go down to speak to them tomorrow. I'll let you know how it goes.
@Three Seasons - My issue is a little bit different than yours since it only affects one motor but I'm curious how your friend determined the ECM was struck by lightening to get insurance to cover it.
I told them to order the new ECM (~$3K) and I'll go down to speak to them tomorrow. I'll let you know how it goes.
As I recall the insurance adjuster took the advise of the marina tech and ordered the ECM. The owner was able to identify the approx lighting strike by reviewing weather data and insurance company claims in the area at the approx time of failure. It’s a long shot but saved him $2500 (at the time).
All the Best
All the Best
Tripsdad
Well-Known Member
Thank you! A long shot but I’ll speak to them tomorrow.
I’m not a mechanic but it would seem strange to me that both ECM’s would go at once. My mechanics changed the fuel regulators on another boat that was having this issue and it seemed to resolve the problem. It’s definitely a frustrating issue!
Hi Captlori,
Hoping you survived your last bout with Covid from last fall. Have you installed cables yet? Our boat went in one week ago, faulted only three times the first day and 30+ times two days later.
This is so incredibly frustrating - still looking for answers - during winter we tested my 8.1 PCM’s on another boat and they never failed also cleaned more cables + & - on everything. Next maybe inspect &/or replace cool fuels (because in was running weird) and replace cables if it works for you.
Thanks
PlayDate
Well-Known Member
If I follow what Tom says and look at the videos....it would appear that you are losing power on the Red and Black wires which in turn causes the display to turn on and off.
Can you put a voltmeter on the red/black wires and see if power drops?
Tom, where is the power supply for his Smartcraft system and what voltage should he see on those wires?
