Single beep, loss of smartview, engine runs, techs stumped....

[Captan Mike]

So been battling a gremlin all season. The basics are the 8.1S with Smartview (manufactured in 2005) in a 2005 DA390.

Sympoms: Intermittently and at random, will get a single beep like ignition turned on or off, and engine will momentarily stumble on starboard engine. (problem is not issue with Port...yet) (if at lower RPM say 1000, will come back at idle (680-700)) if at higher RPM, loss of power for quicker than you read this, and comes back to life. Smartview looses connection, then 50% will come back as normal, other 50% time will have total loss of insturments for that motor. Seems to settle for a bit, then comes back with a single beep and may regain instruementation and start the process over.

So far, all connections on harness, ground, battery checked and no corrision and reset.
Voltage readings on smartview and vesselview range from 13.5 to 14.1

New 50 CB installed (red button, not yellow one)

Ran this morning with Merc Tech, and when happens, laptop still receives data, no loss of communication on CanBus...
.
Installed Vesselview mobile (had one laying around) and no loss of communication of engine data, even during the beep and stumble.

NO FAULT CODES, so it has to be in the electrical supply side right?

This has my completely stumped, and like many searched and searched forums, so will use this to update as my search continues. Seems quite a few had this issue, but no one posted a resolution. My plan is to do that or loose my sanity... whichever comes first!

 

[scoflaw]

Bad connection somewhere. Try running engine with cannon plug disconnected from boat to see if it's on the boat side or the engine side. Jumper pin hole #5 to#6 and power #7 to start engine [crank]

 

[PlayDate]

This is 3rd thread in 2023 where Smart View loses power and the engines continue to run.

In one of those threads the owner replaced the entire SV harness and the problem remained.

It sounds like it is a 12volt supply or bad ground to SV.

 

[Captan Mike]

-John, I would agree except for the fact the engine stumbles, so I really think it's power to the engine being interrupted, just where, cause it can be only so many places.. anyways will continue to update as we troubleshoot further, as we are at the point of throwing on parts.

 

[mratlndmrk]

Interesting...I just started having this problem recently only for me smartcraft just turns off and I lose my gauges. But no interruption in anything else. I only notice after the fact when looking at gauges that it happened. Just turn SC back on and gauges come back.

 

[Captan Mike]

So a little update. No word from techs, so disconnected all instruments and smart view, and just ran Bluetooth. Same issue, so it’s not in the smartcraft system… frustrating as family is here for probably last hot day in Michigan.

 

[PlayDate]

So a little update. No word from techs, so disconnected all instruments and smart view, and just ran Bluetooth. Same issue, so it’s not in the smartcraft system… frustrating as family is here for probably last hot day in Michigan.

Sorry you are going through this. We have had a rash of similar stories on CSR with similar problems and techs that could not figure it out. If the engine is really losing 12 volts it is most likely at the ECM or distributor. I would put a meter on the coil and see if you are losing 12 volts there when the engine cuts out. You will see the voltage drop to zero before the engine stops spinning.

We had one issue a few years back when an owner updated a number of electronics on his dash. In the process, he disrupted the purple wire which daisy chains through the electronics to the engine. As a result, the engine would just randomly quit. It was tough to find but we ended up putting a 12 volt jumper directly to the coil from the starter and the engine behaved perfectly.....no shutdowns. So it was then a process of back tracing the wire to the gauges.

Loose/bad connectors are usually what causes this to happen.

 

[boatrboy]

…… I would put a meter on the coil and see if you are losing 12 volts there when the engine cuts out. You will see the voltage drop to zero before the engine stops spinning.

We had one issue a few years back when an owner updated a number of electronics on his dash. In the process, he disrupted the purple wire which daisy chains through the electronics to the engine. As a result, the engine would just randomly quit. It was tough to find but we ended up putting a 12 volt jumper directly to the coil ………

Don’t all 8.1s have coil packs? I just changed my wires yesterday and mine doesn’t have a distributor.

 

[Three Seasons]

Hi Mike,

This sounds very similar to my 8.1 comm issue.
http://www.clubsearay.com/index.php?threads/communication-issues-with-8-1’s.110654/

Check out this thread. Turned out to be a bad power supply connection on the bottom of Smartcraft at the helm. I basically disconnected it for days running with no gauges and had no engine beeps no RPM drops. Then I reconnected and the problem has been gone all summer.

We chased this down for over 2 years, we have very similar boats hope this helps.

 

[PlayDate]

Don’t all 8.1s have coil packs? I just changed my wires yesterday and mine doesn’t have a distributor.

Yup. You are correct but the same scenario applies to the 12 volts that feeds the coil pack. It is a time consuming process to isolate the problem.

The issue I believe most likely is a power loss from a bad connector or possibly a bad ground. Unfortunately....there is no tester that helps because when it is working ......everything will read fine. Frankly the only way I have found these problems is to get it running and start tugging on the connectors and harnesses.

 

[OllieC]

I'm not sure about the 8.1's vs. the 5.0, however I had a similar issue. Not under load the engine seemed to run fine. Under load it would stumble or stall, beep once then restart, and then do it all over again. I ended up spending $1500 on a non-returnable ECU and it wasn't the problem. The issue was a $75 Crankshaft Position Sensor. Screwed up my whole Summer. No codes or anything. The marina was stumped and I figured it out on my own. I see there's a camshaft sensor on the 8.1's?

 

[techmitch]

I'm not sure about the 8.1's vs. the 5.0, however I had a similar issue. Not under load the engine seemed to run fine. Under load it would stumble or stall, beep once then restart, and then do it all over again. I ended up spending $1500 on a non-returnable ECU and it wasn't the problem. The issue was a $75 Crankshaft Position Sensor. Screwed up my whole Summer. No codes or anything. The marina was stumped and I figured it out on my own. I see there's a camshaft sensor on the 8.1's?

I know it's expensive but graphed live data would have revealed the root cause.
Did you hold on to that ECU?

 

[OllieC]

I know it's expensive but graphed live data would have revealed the root cause.
Did you hold on to that ECU?

Yup - have a spare. I’m using the newer one and the original is in a box

 

[ttmott]

Is Smartcraft / instruments / Vessel View rebooting same time the engine stumbles / stalls?
If so, the only thing common is the keyswitch and ignition wiring. The only other item which is in series with the ignition wiring would be a safety lanyard switch if your boat has one.
That ignition signal is provided to the engine ECM and Relays as well as the instruments through the Smartcraft harness' and J-boxes.

 

[Captan Mike]

Hi Mike,

This sounds very similar to my 8.1 comm issue.
http://www.clubsearay.com/index.php?threads/communication-issues-with-8-1’s.110654/

Check out this thread. Turned out to be a bad power supply connection on the bottom of Smartcraft at the helm. I basically disconnected it for days running with no gauges and had no engine beeps no RPM drops. Then I reconnected and the problem has been gone all summer.

We chased this down for over 2 years, we have very similar boats hope this helps.

Thanks, I reviewed your thread. While similar, with the SmartCraft disconnected, I still got the beep and engine stumble on the starboard engine. You mentioned that when disconnected, meaning no instrumentation, the problem disappeared, which is what led me to try that.

 

[Captan Mike]

I'm not sure about the 8.1's vs. the 5.0, however I had a similar issue. Not under load the engine seemed to run fine. Under load it would stumble or stall, beep once then restart, and then do it all over again. I ended up spending $1500 on a non-returnable ECU and it wasn't the problem. The issue was a $75 Crankshaft Position Sensor. Screwed up my whole Summer. No codes or anything. The marina was stumped and I figured it out on my own. I see there's a camshaft sensor on the 8.1's?

Can I ask how you came to the sensor? Only cause I'm at the stage to start throwing parts at it. LOL.

 

[OllieC]

Can I ask how you came to the sensor? Only cause I'm at the stage to start throwing parts at it. LOL.

That was actually the stage I was in. As mentioned, no one could figure it out. Even the tech at my marina who had a scan tool, which led me to buy a non-returnable $1500 ecm, which I didn’t need. So I started reading more about what sensors I had, and CPS came up in a thread from another site.

I read that others were stalling but not necessarily having the beeping or the same issue I was. I looked up the part, realized I could pick it up at Napa for $70. Took 5 mins to replace and ‘viola’, that was the issue. All it is is a magnetic sensor , that times a lobe or nub (forgive my nomenclature- I’m sure I’ll be corrected) on the crankshaft while spinning. That sensor sends a basic timing message to the ECM as you increase or decrease throttle. Mine went bad, the ECM was confused and stalled the motor. For the 2005 5.0mpi, there are no error codes for when that happens. Mercruiser rectified that on later models.

 

[Jimmy Buoy]

That was actually the stage I was in. As mentioned, no one could figure it out. Even the tech at my marina who had a scan tool, which led me to buy a non-returnable $1500 ecm, which I didn’t need. So I started reading more about what sensors I had, and CPS came up in a thread from another site.

I read that others were stalling but not necessarily having the beeping or the same issue I was. I looked up the part, realized I could pick it up at Napa for $70. Took 5 mins to replace and ‘viola’, that was the issue. All it is is a magnetic sensor , that times a lobe or nub (forgive my nomenclature- I’m sure I’ll be corrected) on the crankshaft while spinning. That sensor sends a basic timing message to the ECM as you increase or decrease throttle. Mine went bad, the ECM was confused and stalled the motor. For the 2005 5.0mpi, there are no error codes for when that happens. Mercruiser rectified that on later models.

Not to hijack the thread, but I had a similar issue recently. Got a replacement Crank Position Sensor (Amazon from China) but it didn't come with the shims as promised and once installed, wouldn't even allow the engine to fire at all while cranking. Put the old one back in which worked fine. Thinking that the sensor was ok, but the connector had been contaminated with oil. Returned the part for a refund, but curious if your part from Napa came with shims and if you have the part number. It's the same Merc part, but I'm not too interested in paying Merc's prices for a sensor that is an over the counter part at any auto store. Thanks!

 

[scoflaw]

No shims on mine. If it didn't work it's probably too short not too long. Measure your original and compare.

 

[OllieC]

Not to hijack the thread, but I had a similar issue recently. Got a replacement Crank Position Sensor (Amazon from China) but it didn't come with the shims as promised and once installed, wouldn't even allow the engine to fire at all while cranking. Put the old one back in which worked fine. Thinking that the sensor was ok, but the connector had been contaminated with oil. Returned the part for a refund, but curious if your part from Napa came with shims and if you have the part number. It's the same Merc part, but I'm not too interested in paying Merc's prices for a sensor that is an over the counter part at any auto store. Thanks!

Mine didn’t have shims either. Unfortunately I don’t have a part number. It was installed back in 2021. IIRC I looked it up under GM crankshaft position sensors. I’m looking now to see if anything rings a bell.