ECM555/PCM 555 and Techmate question.

[vetplus40]

I bought a Techmate tool to clear some error codes from my 2014 3.0 Mercruiser with a PCM-09 module. The motor has the standard 6 pin connector and the advanced 10 pin CAN bus connector. The motor also has a 4 pin connector labelled "Diagnostics" as well.

Recently, I bought a ECM/PCM 555 adapter to check out a boat that I am considering purchasing. Just out of curiosity, I connected my tool and that adapter to the 4 pin "Diagnostics" connector on my motor.The tool first displayed "PCM module found". It then read "ECM module not found, ensure ignition switch is on".

Given that my motor is equipped with the PCM-09 module, I guess I am just curious as to why it has the 4 pin connector as well? Especially, since it appears not to work.

Thanks

 

[achris]

4 pin connector is for the Diacom software adaptor cable.

 

[Fun Times]

I bought a ECM/PCM 555 adapter and connected my tool to the 4 pin "Diagnostics" connector on my motor.The tool first displayed "PCM module found". It then read "ECM module not found, ensure ignition switch is on".

Given that my motor is equipped with the PCM-09 module, I guess I am just curious as to why it has the 4 pin connector as well? Especially, since it appears not to work.

Thanks

That 4 pin adaptor connection on the engine wiring harness side typically marked as Diagnostics for the 555 ECM is also used as an "Depth Sounder" device for the smart craft system mercruiser offers....They must have forgotten to change the sticker for the mercruiser PCM-09 ECM modules that came out in 2009ish....Some models tended to have Diagnostics stickers while some others may have read Depth Sounder....I don't know (or recall) the consistency of the two different worded stickers though between models.

While the ECM may not read on your engine model after plugging it in to the 4 pin connection, while doubtful this happen as I can foresee where the scan tool would power up for a second but then not be able to read the ECM as you described...,Just be sure you didn't blow a fuse or something for that connection as it is the 12volt side.

Below are some past Depth Sounder conversations for reference points if desired.
https://forums.iboats.com/forum/eng...3-diagnostic-port-location-mercruiser-5-0-mpi

 

[achris]

That 4 pin connector is just a Canbus connector. Any Canbus device can plug into it. That includes the Merc specific Depth Sounder.

Now, here's the nasty on the engine's canbus... While the hardware (voltages etc) comply with NMEA-2000, the data protocols do not. While any canbus device can plug in, and get power, unless it uses the Merc specific protocols it no talkies. If you want any 'non Merc' canbus device on the system, you need Merc's 'Gateway', at $400+... Nice, NOT!

And if memory serves me, it's also the connector for dual engine installations. So if you have dual engines, and they are connected and you want to use a diagnostics laptop, you have to remove the connection between the engine first. But I may be wrong (often an these days. :facepalm.

Chris..........

 

[vetplus40]

A friend wanted to use my tool to check his 2003 Mercruiser 5.0. He found a "Canbus" connector on his motor, but we got the same type of error message. I then hooked up to my PCM- 09 Canbus connector and the tool read just fine. I didn't realize that they put a Canbus on an 03 motor. I thought the technology was newer than that.