Thanks for posting this Ian. I got this protocol a few years back from Yanmar. As a comment it think it is also important to note that the engine hours and transmission hours are reset separately, Also this protocol is only for the KYC yachts that have the VCS throttle system (fly by wire). I was the first yacht to upgrade to these throttles so this throttle system is only going to be in yachts (potentially) from build #91 onwards.
For completeness I have listed below the note I got from Yanmar
Process for sorting out Alarm reset on YANMAR 4JH57 with the VCS throttles
If you don’t mind, I can tell you about the following steps on the VCS display to reset these alarms yourself,
1. On the Display press “ENTER”. At this stage, a MAIN MENU will appear with a drop-down list of 6 or 7 items the first item from this drop-down list is “Alarms/DIAGs” which will be highlighted in blue, 2. Press “ENTER” again , at this stage a second drop down list will appear with three items, By pressing the down arrow on the display panel, you will move down to “Network nodes” therefore highlighting “Network nodes” in Blue 3. Press “ENTER”, this will take you to a screen that have a blue arrow at the top left-hand corner and the word “Network Nodes” in a box Now you need to press and hold the left arrow on the display for a period of ± 5 seconds until another box appear with the wording ENTER in it.
Here is where you will need to enter a passcode You can select the number you need by using the up and down arrow and then to move to the next number to the left you press the left arrow, The code is 1191 : please note that there is place for 5 digits, and we only use 4 therefor when you come to the 5th digit merely press the right arrow which then will bypass the 5 the digit and take you to where the wording ENTER on the display will be highlighted in blue.
Now press ENTER on the display.
The above action will allow you to continue to the next step where we will disable or rest the maintenance alarms, By pressing the left arrow, you will close the menus you were in one by one until you reach the MAIN menu page again with “Alarms/DIAGs” still highlighted in blue Stay on this main menu, now you will notice that there are more items on the drop-down list.
By using the down arrow move down until “Utility” is highlighted in blue Press “ENTER” this will open the Utility menu with its own drop-down list, Move by using the down arrow until :Reset maint time" is highlighted in blue Press “ENTER”
Now you are in the screen where we need to reset the alarm, You can do so by pressing the down arrow to where the word RESET is highlighted in blue and when you press ENTER you will reset the alarm which will sound again when you reach the next 250 hours of service, The same you can do for the Transmission alarm.
Alternatively, if you feel that you don’t want these alarms you can move to the block where it says ARMED which will then be highlighted in blue and at this stage when you press “ENTER” you can DISARM the function of you feel that you would be able to remember to do the services yourself.
I know the above seems like a mouth full, but that is unfortunately the only way I can help you now unless you want to sit with the annoying alarm till you reach a spot where there is a reputable Yanmar service agent who can then reset the alarm for you.
