Thanks BUP. First ,I'll wait and see if the oil pressure sensor swap do anything, then I'll swap the SC gauges.Swapping the ECM555's previously didn't make a difference, hoping that maybe the SC swap brings some results.

Hello ! We own an Epic V23 boat that has a mercruiser 8.1 motor.
Apparently no one can help me .. Ive called multiple people in multiple locations.
I found this forum doing research.

When I hook up the computer the error codes I get are the following

Fuel LVL2 CKT H
5VDC pwr 2 L

We have been trying to get this boat to work for 3 months!!!!!!!!!! and Ive had it, i need to figure it out. Can someone pleaseeee help me??!

The boat starts fine, when we take it out as soon as we go over 3300 RPMs the alarm stays on until we go back to neutral. The message on the screen says "Sensor power supply voltage is low" when I select more I get . STBD system failure 217.

Is it possible for you to guide me ? Thanks in advance

I see your post and responded to the same in another section up here. One post we will see it just give it sometime. Heck we all have jobs I think ? Trying to be funny.

2010 350 MAG MPI DTS with emission control
 

I've been to 2 mechanics, have spoken with 4. Smartcraft giving me a STBD fault code 19. Hooked up the Mercruiser G3 scanner. Saw fault codes 219 and 315. Everything is fine per G3 and mechanic. Smartcraft continues to have system fault STBD 19, even after clearing codes. 2 mechanics suggested replacing the STBD O2 sensor post Catalyst. I did, still getting the same smartcraft STBD error code 19.

Any ideas?

Check with it on a scanner, make sure ECM does not think engine is in neutral, had that happen on my old 6.2 boat. Switch throttle cable were it mounts to exhaust was cracked.

Spec Only says he checked it with Diacom and has overspeed showing on the scan as well.

question is do you have the shift in gear switch ? If so that could be your problem. If so it will be located on the shift plate.

If you do not have it make sure you check both engines for it. Just saying as if one engine has it and the other does not ? 2003 I believe all smallblocks should of have the shift in gear switch. Possible swap over if both engines have it to see if problems follows or stays. next possible could be crank sensor and again as said before swap tachs if none of this fixes your problem. I would clear the code and see if it comes backs and or follows especially swapping the tachs over.

Do have any other fault codes in the scan - look into history for any other faults.

POST # 14 how much training do these mechanics have with Mercruiser PCM 09 Cayalyst operation, faults, data fields- CDS G3 Live data , OBD -M 1 faults OBD-M 2 faults. Have to ask because this controller system / catalyst operation is a whole completely different animal compared to ECM 555 & PCM 555 plus the scanning knowledge along with the indepth of it ?.

You know you have 4 - 02 sensors ? 2 - 02 sensors per side - a pre cat 02 sensor and another one after the cat


CDS G3 fault code # 315 is starboard catalyst failed diagnostic test and the catalyst might be DEFECTIVE. They (mechanics) will have to check the live data screen to see the reason why for this code and if that is a failed catalyst for sure or a related problem. Just saying A real defective catalyst can cause engine damage so I am asking how well or NOT well is your engine running ?

FYI - Fault code # 316 is precatalyst 02 sensor B failed rich to lean response time. Have to check Live data screen for this code to for the reason and can be a defective pre cat 02 sensor.

fault code # 19 guardian overspeed - this probably is because of the of fault code 315 as it could possible mean the engine is going faster than guardian currently thinks it should. More detailed info about this is engine rpm is exceeding guardian rpm limit at time of the a real fault.

Thanks much for the information. I'm beginning to realize many mechanics don't know a lot about the newer emission control systems on boats. Aware of the 4 sensors. Was told by 2 mechanics it was down stream O2 Starboard side, whether a bad sensor, bad wires, bad something, but that it was the O2 sensor. Guardian fault code word for word is, "STBD system fault 19 Catalyst. Catalyst is not working properly. Emission control problem. Service engine soon." Per mechanic engine is running good. No issues. All other readings good. I think boat sat for most of this spring, summer. Thinking maybe it is just dirtied up? Not sure, will have to take to a third shop to see if they can figure it out.

Location as in where are you and boat located ?

Have you ran the boat out of gas - running hard any form of misfiring and or low fuel level or the engine runs out of fuel will blow a hole in the catalyst sub strake. FYI.

Misfires are really bad for CAT engines overtime.

Also cat could be restricted

also their is a test port in the exhaust to test reading of the exhaust emissions. You can stick a real wide band hand held in the exhaust access port hole and see what the air / fuel ratio is to. Just saying

You have to ask the techs how much CAT and PCM 09 / OBD factory training they have. Find one that is current. I am very current just saying

Sodus NY

Not run out of gas. Was running 30-40 when I noticed alarm come on.

Guessing restricted flow, but really don't know. My logic is the boat sat most of this year. Had 70 hours on it. I ran it for 3 staright days and on third day it alarmed. Maybe some cataclean through it. If that doesn't clean it up, on to the next step.

Come on up to Lake Ontario! You sound very current on OBD. Need to find one that is up here. Seems like most are not too familiar. Engine serial number: OW987782

Truly appreciate your responses. Good knowledge and have learned more on line, than in reality. If you know the CAT guru up this way, let me know. Otherwise I'll have to part with 12 of my best friends named benjamin for a new CAT and an install.

Michael