That helps a lot!! ThanksThat is a MEFI (1 to 4) connector and while there are not many codes can be read, if there is one it can be done as your pic shows. Use a 12V resistor LED or a voltmeter with a tone function
Fantastic tutorial, can't wait to try it out!!Like mentioned above, if you're just wanting to read trouble fault codes on the MEFI ECM's only type then the following way using a multimeter is a safe and easy effective way to do it...
If you are wanting more viewable data then maybe checkout a MR500 Marine Scanner for your engine manufacturer model on both Ebay and Amazon as it may be of some help too though seemingly pricey as well.
great, I'll use the clipDon't know of any Merc which used the MEFI 5, it was only used Indmar and VP