Merc 5.0 EFI alarm beeps while cranking

[Sarges12]

I have a 2001 290 Sundancer and I’ve been experiencing a problem with the engine alarm and can’t figure it out. After waiting for the 2 long beeps the alarm beeps again while i hold the toggle switch down and the engine is cranking. It then stops when the engine starts, oil pressure and temperature is normal. I’m stumped why it beeps while cranking. Suggestions on what to look for?

 

[scoflaw]

what ecm ?

 

[Sarges12]

I assume orginal. Part #861925T3
I’m going to the boat tomorrow. I’ll check it out.

 

[scoflaw]

The 555 module is way more complex than the Mefi 3. If it's the Mefi it should be easy to track down.

 

[Sarges12]

I checked the ECM today. Not sure how to tell which module it is.

 

[Strecker25]

This might help.

http://fox-marine.com/index.php?route=information/information&information_id=7

What MEFI version is my ECM (MEFI-1, 2, 3, or 4)?
If you aren't able to obtain the MEFI version from an email or phone call to the engine manufacturer, then unbolt the ECM mounting bolts (no need to disconnect any wires/connectors) to reveal the sticker with a GM model number on the backside of the ECM. Correspond the GM model number to the MEFI version below.
MEFI-1: 16159919, 16189069, 16220371, 16234539
MEFI-2: 16210729
MEFI-3: 16237009, 16236999, 12489488, 12489493
MEFI-4: 12569494, 12575479, 88962717, 88962718, 12584052

 

[Sarges12]

Thanks, I’m going back to the boat tomorrow to change thermostats before the season starts. I’ll check the back of the ECM and take it from there.

 

[scoflaw]

All you need is your engine number. You either have a Mefi 3 or a 555.

 

[Sarges12]

So the ECM Module is a MEFI-3. I checked the back of the ECM while at the boat.
What should I look for as far as the two extra beeps I get while cranking the engine over?

I get no other alarms while under way. Only when the engine is being started.

 

[scoflaw]

Quick way would be to have it read with the tool.
Overheat, low drive oil, low oil pressure or a bad sensor connection would make it sound.
Maybe low voltage from the cranking draw....just a guess.

 

[Sarges12]

I’m on the side of a bad sensor or voltage issue. It does it all the time, whether I’m starting it cold or after running it for on a trip. While under way, oil pressure, water temperature and volts all normal.
I’ll be having it read before I launch.

 

[David Z]

Hello, new to this forum. But this thread seems helpful to my current puzzle...
My 290 Sundancer year 2000 has a good engine alarm self check on STBD, but PORT has gone silent. Audio Warning System test per the SELOC manual is good at the console, I tested the port drive gear reservoir (SELOC says the level switch closes when level is low to cause the alarm) and learned when I connected the wires leading to the switch, I get NO ALARM.
With a good audio warning system but no alarm when I send a valid signal, SELOC concludes there is a bad wire from the engine. But it gives me no clue where that wire starts from... (it tells me it's tan/blue, like that's supposed to help me find it...)

My owners manual wiring diagram shows the oil pressure switch, the water temperature switch, and the drive gear reservoir level switch all having inputs to the alarm. What is NOT shown is what is the source of the self test (two beeps when first selecting "run" to start the motor). Is the ECM the source of the self test? Do all the inputs to the alarm go through the ECM before heading forward to the Audio Warning Horn?

If yes to either question, any reason NOT to just swap the ECMs to diagnose if the ECM is function isn't right? Note, both engines run fine, I just don't want to run without an audio warning of engine trouble.

 

[Cool Waters]

Try wiggling engine 10 pin plug that connects engine to boat. That brought mine back.