Lost Engine Com message

Cleach

New Member
Mar 11, 2022
23
Boat Info
Sea Ray 320 Sundancer
Engines
496 Mag x 2 with Bravo III
I have a 2006 SeaRay 320 with twin Mercruiser 496 engines. One of my engines keeps giving me a Lost Engine Com message. The RPM fluctuates and sometimes the engine quits when this message happens. It is intermittent but happening more and more often. Any suggestions as to where I should look for the problem are greatly appreciated.
 
Sounds like an phantom electrical connection problem.
I would be pulling all the electrical connectors apart on that engine and ensuring there is no corrosion and they are tight. Might even be a pin on one of the connectors got pushed back in the connector
 
Sounds like an phantom electrical connection problem.
I would be pulling all the electrical connectors apart on that engine and ensuring there is no corrosion and they are tight. Might even be a pin on one of the connectors got pushed back in the connector


Do you know how many connectors are in the system and where they are located (one at the engine and one in the instrument panel?).

Thanks.
 
Wow! Thanks a bunch for the heads up.
 
I cleaned all the contacts and used dielectrode grease as well. I still am getting the the lost engine com display along with an rpm reduction to 1000. Any more suggestions? Can I switch the ECU from my other engine to the malfunctioning engine to see if the ECU is he problem or is that a bad idea. Could it also be at the instrument panel gauge?

Thanks a bunch.
 
Did you clean the cannon plug connection and the 3 plugs that go to the PCM? Do you lose your gages when the engine quits?
 
Is the cannon plug the big round blue one on top of the engine that goes nowhere? I will clean it as well. I did clean the 3 plugs that go into the PCM. They looked good. I will clean the panel gauge connectors next. I did loose the panel gauges when the lost engine com warning came on.

I really appreciate your help. I and the boat are in Mexico with very little competent help available.

GetAttachmentThumbnail
 
Cannon plug is the big black round 10 pin connector located at the rear of engine. Sound like the purple wake up wire is not getting voltage from the red/purple wire at the helm.
 
Well, after a long and sad tale of less than competent mechanics, one of them finally figured out that it was my PCM by switching the port and starboard PCMs and seeing that the swap did cause the starboard engine to have the same "Lost Engine Com' error as the port engine had.

I guess the new ones come standard with programming for the starboard engine and that you need the MerCruiser programmer to change new PCMs to fit the port engine. My mechanics is going to contact MerCruiser and see if we can send the old PCM to them and have them program a new one to fit the port engine. Any suggestions?
 

Forum statistics

Threads
112,950
Messages
1,422,893
Members
60,933
Latest member
juliediane
Back
Top