LIN Transceiver require reference voltage between 9-18V DC according to the LIN Protocol Specification. You need to have an external reference voltage to PIN9 of the DSUB connector. This is applicable to both the Kvaser Leaf Professional LIN as well as all Kvaser Hybrid series interfaces.
For users that do their own programing with canlib/linlib SDK, a status of linERR_NOTFOUND will be returned if the LIN Transceiver doesn’t have reference power.