Local Interface Network Module - Operation

OPERATION

The Local Interface Network (LIN) module contains the circuitry of a LIN slave node, which provides source current for and communicates the switch or sensor states of the Electronic Vehicle Information Center (EVIC) switch pod, the remote radio switches and the horn switch over the LIN data bus to the Steering Angle Sensor (SAS). The SAS is both gateway to the Controller Area Network (CAN) and a LIN master node. The LIN master node in the SAS provides a clean ground and fused B(+) current for all of the switches and sensors on the rotating steering wheel through the LIN slave node circuitry of the LIN module as well as for the Light Emitting Diode (LED) back lighting of the steering wheel switch pods.

The LIN slave node continually monitors all of the hard wired steering wheel switch circuits, while the LIN master node continually monitors the LIN bus data. The SAS reads the electronic message inputs received from two LIN slave nodes, one integral to the LIN module or speed control switch pod and one integral to the multi-function switch. The SAS will store a Signal Not Available (SNA) code for any LIN bus input errors. The SAS allows communication through the CAN gateway with other electronic modules in the vehicle over the CAN data bus. Therefore, any DTC information can be retrieved using a diagnostic scan tool connected to the Data Link Connector (DLC).

The hard wired circuits between the LIN module and the SAS may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin out information and location views for the various wire harness connectors, splices and grounds.

However, conventional diagnostic methods will not prove conclusive in the diagnosis of the LIN slave or master nodes, the SAS or the electronic controls and communication between modules and other devices that provide some features of the LIN bus system. The most reliable, efficient, and accurate means to diagnose the LIN slave or master nodes, the SAS or the electronic controls and communication related to LIN bus system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.