2002 Volvo penta Gxi 5.0 beeping issue

[gucio1]

Hi guys
New season new issues and it looks like I need your help again

Took the boat out for the first time this season. Looked like everything was going well. Drove it for about 15 min accelerated to about 40-45km/h as it was a little choppy on the water. Went to a marina and went around slow pretty much at idle for probably 15-20 min. Went back out into open water accelerated to about 40-45 again and about 1 min in the beeping started. Did not see anything obvious, turned the engine off and restarted and the beep was gone. Rode around for a while (similar pattern to the one above) and the beep started again. Once again turned the engine off and started back up to no beep. When the engine is beeping there is zero effect on the boat performance it behaves exactly as it would under normal conditions.

Is it possible that there is a loose connection somewhere? I really have no idea where to check I got this boat late last season so not too familiar with the engine yet. I winterized it myself so maybe knocked something loose when I was working on it last year.

Hope you guys can pint me in the right direction.
Engine S/N: 4012071429
Drive S/N: 4202037929

Thank you in advance

 

[alldodge]

What kind of Beep? Is it constant, every couple seconds or other?

 

[gucio1]

double beep every few seconds.

 

[dubs283]

There is an active fault when the beeping occurs. You must use the correct scan equipment to verify which fault is active plus investigate any/all freeze frame (stored/inactive) faults and data.

WAG based on info provided is cooling temp related

 

[alldodge]

2 beeps means a code has been set
In most cases I'm finding its the exhaust sensor, thinks its a bit to warm. Only way to know for sure is with a scanner

 

[gucio1]

2 beeps means a code has been set
In most cases I'm finding its the exhaust sensor, thinks its a bit to warm. Only way to know for sure is with a scanner

Just to understand this better. Once the ode is set shouldn't it keep beeping even after I turn the ignition off and back on? Also as suggested above if it is a cooling issue wouldn't it persist once I restart the boat.
I may not have been clear above : the beep starts I shift into neutral, turn the ignition off and turn it right back on. From the beeping to the restart maybe 30 sec. After that no beeping for a long time.

Thanks again for looking guys your knowledge is vast.

 

[dubs283]

A key cycle clears all active faults. When you are hearing the beeping that means the fault is active (currently happening). When the fault is no longer active due to threshold no longer exceeded or shutting the engine off/ key cycle the fault is then stored for later information and is no longer active, hence no beeping

Overheat issues can take a while to occur, even not long after they do happen and can happen at higher rpm then go away at lower rpm and vice versa. Keep in mind we can only speculate about your issue based on info provided by you

 

[gucio1]

Thank you for the explanation. One more question for clarification. First time it happened the beeping did not go away and I tried bunch of stuff. Going at different speeds, idling etc. Nothing stopped the beeping except for the key cycle. Just hoping this might point to something specific.

Also do you guys know based on the info about my engine if the simple diode/paper clip method will work for me for reading the codes?

Thanks again

 

[alldodge]

Yes the diode paper clip will work. Can also use a multimeter that has a tone setting on ohms. Instead of seeing the flash the meter will beep

 

[gucio1]

OK did it. Got code 44 which looks like has something to do with knock sensor unless I am looking at the wrong tables.. Do I need a new one?

 

[alldodge]

OK did it. Got code 44 which looks like has something to do with knock sensor unless I am looking at the wrong tables.. Do I need a new one?

The AHA moment
Would you happen to be running gas with a octane rating higher the 87 maybe?

 

[gucio1]

No just regular 87. It does have the fuel stabilizer in there from the winter could that be it? Would you be able to tell me where I would find the sensors on my engine?

 

[alldodge]

The ECM checks to see if the knock sensor is work when the motor is first throttled up after restart. The ECM advances spark to far for milliseconds to see if it can detect a knock. If it does, timing goes back to normal and all good. If it cannot make it knock, then it sets code 44 meaning it doesn't know if the knock sensor is working.

Merc does it this way and maybe VP does it every so often but its for the same reason. Either way the same test and same result. If higher octane fuel is used this can also cause it because high octane burns slower

You can have up to 2 knock sensors and they would be screwed into the side of the block under the exhaust manifolds. Most motors only have 1 on the starboard side behind the starter. The standard GM knock sensor is all you need, no need to spend money on a VP or other marine one with special paint

Its not in a water jack just on a boss area so no worries when removing. When installing new do not use thread sealant, just bare threads. Tighten to 15 Ft Lb or 20 Nm, and do not over tighten

 

[gucio1]

Thank you very much for your advice. I will see if I can locate them tomorrow. Is it at all diagnostic to know that it takes a long time before the code gets triggered?

 

[alldodge]

Is it at all diagnostic to know that it takes a long time before the code gets triggered?

Normally it happens real fast, but sounds like its intermittent. It works then it doesn't. Could be a bad connection on the sensor. It has a plastic clip that snaps on top of it. Some times the top gets corroded

https://www.amazon.com/Sensor-Switch-Mercruiser-806612T-Mercury/dp/B01MXW22I6

 

[alldodge]

BTW it maybe able to done away with. Code 44 was only used on MEFI 2 and 3 models. Since then they found it does more harm then good. It can be turned off but need tuning software to do it. The caveat is that the ECM program cannot be locked and most are not. Need something like MEFI Burn and can turn it off, I turned mine off

 

[gucio1]

Hey, quick update. Replaced the sensor. I could only find one on the starboard side of the boat. Took the boat out and it still does it but no real rhyme or reason when. And again it will beep and then as soon as I cycle the key it is fine again. Could it be the wire/connector attached to the sensor?

 

[alldodge]

Could very well be the wire connection
Don't have a good wiring diagram, but finding pins
27 Knock 1+
28 Knock 1-
29 Knock 2+
30 Knock 2-
But does not mention J1 or 2 but Merc should be J1

Having only one then should be 27 and 28
Should be a Bark Blue wire

 

[gucio1]

Ok one last question before I disable the code.
It looks like the beep gets triggered when I am going above 45 km/h and turn... I can do anything I want under 40

Again as soon as I key cycle alarm goes away.


Does that give you any ideas?

Thanks again for all the help

 

[alldodge]

Think this is 2 separate issues
Code 44 is set by the ECM trys to make the engine knock and it is unable to do so. When Merc sets 44 then power is reduced. Unsure if VP does the same.

As before 2 beeps means active fault. Only way as I see it is to be able to scan for codes when this happens. After a key cycle it clears because its no longer active.

Without more real time info, then I'm leaning back to exhaust temp is getting either to high, or the sensor thinks it is