9.3.4 Connecting the Debugger to an RJ-45 Target via an RJ-45 Type Cable
The MPLAB ICD 4 In-Circuit Debugger has an RJ-45 connector for communication to the target. Connect the RJ-45 type cable into the RJ-45 connector. Connect the other end of the cable to the RJ-45 connector on the target.
Refer to the figure below for the pinouts for this connection.