Speed Control System
To avoid serious or fatal injury on vehicles equipped with airbags, disable the Supplemental Restraint System (SRS) before attempting any steering wheel, steering column, airbag, Occupant Classification System (OCS), seat belt tensioner, impact sensor or instrument panel component diagnosis or service. Disconnect and isolate the battery negative (ground) cable, then wait two minutes for the system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the SRS. Failure to follow these instructions may result in accidental airbag deployment.
The hard wired inputs and outputs of the speed control system may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, 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 Local Interface Network (LIN) slave node integral and internal to the speed control Steering Wheel Switch (SWS), the Steering Column Control Module (SCCM) integral and internal to the multi-function switch, the Antilock Brake System (ABS) module, the Powertrain Control Module (PCM), the Adaptive Cruise Control (ACC) module or the electronic controls and communication between modules and other devices that provide some features of the speed control system. The most reliable, efficient and accurate means to diagnose the LIN slave node, the SCCM, the ABS module, the PCM, the ACC module or the electronic controls and communication related to speed control system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.