MEFI 3 (16237009) vs MEFI 3 (16236999) help needed
 

Hey everyone,

I am having a difficult time in getting any clear answers on my current situation and hope that someone has the time and knowledge to help me out here!

Situation: ECM (sent to OBD and confirmed its toasted)
Boat: 2000 Shamrock 246 wa
Engine: 5.7l plus EFI (350cid)

This inboard engine says seamaxx on it. The part I need exactly is a MEFI 3 Delphi ECM model number 16237009 but a member on these forums has told me that he has a MEFI 3 Delphi ECM but its model number is 16236999. Can anyone help me out in determining if this is compatible with my engine (after getting it tuned ofc) or will it not work simply because its a different model number period.
If there is any additional information required please let me know I will respond very actively and quickly!
Thank you for all your help!

Either ECM will work on that engine. However, the calibrations are not directly interchangeable. Meaning, you can not just download a cal for an 009 into a 999 ECM. The cal can be converted though. There are a few guys that can do that. I'm not sure if ODB is capable of converting your file or not. If not, then you would have to find someone that can or find 999 cal for that engine (if it even exists). I'm not sure about your particular engine but Merc had some engines that used both over the years. The 502 mag for instance, used both a 009 and a 999. You could use either. Your engine may have only been available with the 009. That is a question that I can't answer.

So, you have a few choices. Either find a 999 cal for your engine and use the ECM that you found, have your 009 cal converted to work with a 999 ECM and use that one, find another 009 ECM and load your cal or use a 999 and have a cal written for it. It will probably need to be tuned in the boat though.

As far as the harness, sensors, etc are concerned, there is no difference. Give a call if I can help.
Eddie

Here is some additional info thru what I recall Merc training that applies

ECM 16236999 will have a moving desired idle mode that will operate between 0 % and 5 % throttle plate opening, By doing This - will allow more consistent speeds at part throttle engine running speeds since the ECM will try to maintain a very steady rpm within that range. On inboards and ski inboards (Merc) apps as well used ECM 16237009 in which had a load anticipation mode that additional IAC counts are added when in gear and then removed when going back in neutral.

MEFI 3 ECM has a password protected EEPROM so not just anyone can go into it and reprogram it. .

also with moving desired RPM mode (MEFI 3 16236999) the rpm speed of idle to around 1200 will be maintained more constantly plus will make the transition from idle rpm to higher throttle positions a lot smoother but at 5 % or greater throttle position SENSOR setting the moving desired rpm mode is not active then.

I would estimate OBD could do the work.

Great information guys I really appreciate it!

My biggest concern is that my good friend had found 16236999 at a nearby boat junkyard (claims that was the exact model number but I didn't see in person) said that he tried it in the boat and it fired up BUT he says that between the 16237009 and 16236999 that there is a difference in how many pins there are. 009 had 13 pins and 999 had 16 ....so thats our biggest concern at the moment with grabbing this part from the nice gentlemen on this forum who informed me that he has it available right now. ALSO to note he told me that it was pulled off a 350cu engine and ours is a 350cid which I don't know if that makes a difference

***I am not by any means a very mechanically inclined guy so i apologize for the my horrible understandings on some of these issues but I am learning fast lol

SO my next question would be about the connections -Eddie noted at the end of his reply that everything should connect the same but is there possible anyone who can confirm that the connections are exactly the same? same amount of pins - same harness etc? I'm just being extra cautious as buying a part for lots of money to learn it doesn't fit is fairly depressing lol and I'm just trying to avoid that because as I said before that my friend claimed to have tried the 6999 one but told me that it has more pins. Wish I was there to testify this was true or not

there should be J 1 and J 2 with - 1 thru 32 for J1 and 1 thru 32 for J 2 connections but not all are used

Some of the differences

7009 was used a lot for inboard MIE apps and again had load anticipation mode, It also had an signal from the neutral safety switch on the transmission side that went back to the ECM terminal J2 -20

this was used on the 454 and 502 MIE / inboard apps also

mercruiser MIE were inboard apps and Mercruiser MCM were sterndrive apps

more info I am having computer problems - I think OSO is a virus farm for my computer. Jeepers and I have webroot what junk .

anyways trying recall - MEFI 3 for the MCM Alpha merc there is a shift switch circuit from the ECM J2 - 9 terminal through the shift switch, to ground that is used and of course bravo;s did not use that ( shift switch)

Mefi 3 only the V 6 4.3 and the smallblocks 5.0 and 350 had a low fuel pressure sensor that if the ecm inputs was seeing low fuel pressure for 5 straight seconds a warning horn would sound

the FP sensor was installed for efi tbi in the throttle body unit and fo MPI the FP sensor was installed in the port fuel rail - rear engine side.

also for the 454 certain year(s) MEFI 3 had 2 knock sensors for the ECM inputs

these also had there own circuits and inputs to the ECM MEFI 3

Thanks for all of that in depth information BUP I am able to follow a majority of what you have said and in short my question then is even though there is slightly different number of pins between 7009 and 6999 could I get away with the difference in the 6999 by simply having it calibrated / reprogrammed to my engines specs ALTHOUGH a pins are slightly different? Everything connects like 7009 Ecm does but 6999 has 3 extra pins I believe

Yes, as long as you have the correct calibration, the ecm will just plug right in and work fine.

However, just because the ecm is from another 5.7L doesn't mean that it will have the same cal, especially if they are from different manufacturers...ie. from a Merc engine to a Volvo. They could have different size injectors for example. Just be sure the cal you get is for your exact engine. That may be the hard part.
Eddie