Чтобы зарегистрировать техобслуживание, нужно использовать команду unit/registry_maintenance_event:

svc=unit/registry_maintenance_event&params={"date":<uint>,
					    "info":<text>,
					    "duration":<int>,
					    "cost":<double>,
					    "location":<text>,
					    "x":<double>,
					    "y":<double>,
					    "description":<text>,
					    "mileage":<double>,
					    "eh":<int>,
					    "done_svcs":<text>,
					    "itemId":<long>}

To create, edit, or delete maintenance properties (the Service Intervals tab):

svc=unit/update_service_interval

required parameters:

{
	"itemId":<long>,	/* unit ID */
	"id":<long>,		/* service interval ID (only for update and delete actions) */
	"callMode":<text>	/* action (create, update, delete) */
}

Optional parameters:

{
	"n":<text>,	/* service interval name */
	"t":<text>,	/* description */
	"im":<uint>,	/* mileage-based interval to be done once in every N kilometers */
	"it":<uint>,	/* days-based interval to be dine once in every N hours */
	"ie":<uint>,	/* engine-hours-based interval to be done once in every N hours */
	"pm":<uint>,	/* previous mileage, km */
	"pt":<uint>,	/* previous days */
	"pe":<uint>,	/* previous engine hours */
	"c":<uint>	/* count of service intervals that have been done */
}

[
	<long>,			/* number of service interval */
	{
		"id":<long>,	/* service interval ID */
		"n":<text>,	/* service interval name */
		"t":<text>,	/* description */
		"im":<uint>,	/* mileage-based interval to be done once in every N kilometers */
		"it":<uint>,	/* days-based interval to be dine once in every N hours */
		"ie":<uint>,	/* engine-hours-based interval to be done once in every N hours */
		"pm":<uint>,	/* previous mileage, km */
		"pt":<uint>,	/* previous days */
		"pe":<uint>,	/* previous engine hours */
		"c":<uint>	/* count of service intervals that have been done */
	}
]