2020 242se reoccurring BCU error

[Daddy Fat Sacs]

So we own a 2020 242se and have zero issues with it until as of late (3-5 outings) it’s now been at the dealer a total of 4 times with the same issues reoccurring. BCU error, check engine, we’ve had the dealer clear the code several times now and could never get the code to duplicate of course either on land or during water tests. Each time, having my luck it would come back on briefly, go off once in the water, then at some points we would lose all throttle repose of either forward, neutral, or reverse. Would have to cycle batteries on/off for the control drive to function properly again. Once I got home to flush engines, you guessed it....BCU or check engine would come on. They have found a faulty battery switch and the latest thing that is happening is when the house battery is switched on ONLY....communications error for BCU, port, and starboard came on this last time. Turn on both house and starter and the error codes go away. So far dealer nor Yamaha can pinpoint the issue directly. Frustrating for both us and our dealer is an understatement. Nothing like trying to chase an intermittent problem for weeks now. I highly doubt anyone else has had these same problems....but if you have....what was the diagnostic of the root cause please? Oh forgot to mention that when in float mode or just the house batt on, the starter is still showing active current on the starter batt, which my dealer said should not be the case. I’ll update as it comes

 

[marcham]

If there's stray current on the starting battery, then the dealer should be able to trace it and diagnose....sounds like a short or bad ground.

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I presume they've tested wiring for high resistance ? Have they swapped the ecus?

It sounds like they found a symptom but haven't put the time in to find the cause or they just don't have someone experienced with electrical troubleshooting....

 

[mrcleanr6]

As mentioned a bad ground will cause all sorts if issues like this. A bad or poor quality battery will also a bcu error.

 

[Daddy Fat Sacs]

If there's stray current on the starting battery, then the dealer should be able to trace it and diagnose....sounds like a short or bad ground.
I presume they've tested wiring for high resistance ? Have they swapped the ecus?

It sounds like they found a symptom but haven't put the time in to find the cause or they just don't have someone experienced with electrical troubleshooting....

As mentioned a bad ground will cause all sorts if issues like this. A bad or poor quality battery will also a bcu error.

I’ve actually had the service manager has been the one looking at it and doing the 500 different tests to try and chase the problem. Definitely don’t have cheap batteries and their not bad, both show around 12.6-12.8 without the engines started. We just were able to identify the different switches being on/off by accident. The last time I dropped it off, I stayed there while he was on the phone with a Yamaha tech and both were trying all sorts of tests to identify the problem for nearly 2 hours. I wish it was an easier way to streamline the issue, but from reading thread after thread regarding BCU errors, I don’t think I’ve ever come across where anytime was easier to identify the issue(s). Want to clarify that I’m not trying to defend anyone, but I have personally seen/heard my dealer try to troubleshoot and could never get the error to duplicate after clearing. Hopefully this gets resolved sooner than later.

 

[FLJetBoater]

Any luck with this? I’m having intermittent BCU errors after sitting at the sandbar for a few hours. Engine won’t start. Turns over then BCU error then it stops. Cycle or wait for a few mins and then it all of a sudden works again.

 

[FLJetBoater]

I noticed some rubbing makes on my jets. Could the buckets either be coming down too far or somehow slightly out of alignment?

 

[mrcleanr6]

its your batteries. there have been a few instances on the forum with this. people add a battery or change their cheap dealer supplied batteries out for good one and problem goes away. the electronics are sensitive to low voltage so after sitting awhile your drawing the battery down too far.

 

[FLJetBoater]

its your batteries. there have been a few instances on the forum with this. people add a battery or change their cheap dealer supplied batteries out for good one and problem goes away. the electronics are sensitive to low voltage so after sitting awhile your drawing the battery down too far.

The last time happened after a 30 min run. Backing into the sandbar still in 3-4 ft of water. Went to shift from rev to fwd and both engines died with BCU errors. Hopped in water and both buckets stuck down

 

[mrcleanr6]

Ok well that may be a different issue then

 

[SunnyD]

Not saying it's the same issue, but first time out with my 2020 242 se, I had a bcu error after docking killing engines. Upon the next start a minute later a bcu error occurred. Though I broke it. After frantic searching and reading. I got it out of the water and saw that one bucket was closed and one half open. I disengaged the buckets and reset the stuck one. I also adjusted them to be in alignment since they seemed to be a bit off. (pic below) Not sure if this mattered or not.
I learned that you should never kill the engines out out of neutral or with the wheel hard over. I put a band on the wheel to show center and make sure it's there before killing the engines.

 

[mainchannel]

Here is what started my BCU nightmare Friday night. The stick was long enough to stay in and after switching batteries off and on , the cup would reset then the stick would move around and keep setting alarm off. Never saw it until the next morning on the lift.

 

[mrcleanr6]

i had the same thing happen recently. only twice since i have owned the boat have i gotten an error where my shift and throttle would not work. it was just a simple turn off batt switch for 2 min then turn back on to reboot the optimus system and all is well. just a glitchy boot up. recently i got one though that would not go away and it was right after i beached the boat and tried to back off beach a little as the tide was going out. i must have kicked up something that got caught in the one shift bucket. after 4 reset attempts i jumped in and wiggled the buckets back and forth to make sure they were clear, did the batt reset and all was back to normal.

 

[FLJetBoater]

i had the same thing happen recently. only twice since i have owned the boat have i gotten an error where my shift and throttle would not work. it was just a simple turn off batt switch for 2 min then turn back on to reboot the optimus system and all is well. just a glitchy boot up. recently i got one though that would not go away and it was right after i beached the boat and tried to back off beach a little as the tide was going out. i must have kicked up something that got caught in the one shift bucket. after 4 reset attempts i jumped in and wiggled the buckets back and forth to make sure they were clear, did the batt reset and all was back to normal.

I was having many many BCU issues. Narrowed it down to sucking little stones up backing off sandbars using too much reverse. Now, I only put it into reverse enough to move slowly and no further, and haven’t had an issue since.