7-5 check control unit communication

[Chris Mangnall]

I am getting a port P engine 7-5 communication error and that engin will not start, the starboard S is fine.
When the twin engin single station cable is switched port to starboard and starboard to port the the same port 7-5 code apeers BUT the P start button starts the P engin and the P throttle controls it, but nothing from the S side. Does anyone understand, why this problem is occurring?
is the problem with the port side of the twin engin single station splitter cable?
DF300s suzuki 4' nmea dials suzuki fly by wire throttles and start trim

Thanks for any help
Chris

[Proline32express]

I'm having the same issue port motor Started a week after changing the shift actuators 2013 df300s. 440 hours