Battery Electric Vehicle Telematics
To avoid serious or fatal injury on vehicles equipped with airbags, disable the Supplemental Restraint System (SRS) before attempting any steering wheel, steering column, airbags, airbag curtains, knee blocker, seat belt tensioner, impact sensor or instrument panel component diagnosis or service. Disconnect the Intelligent Battery Sensor (IBS)/negative battery cable assembly from the negative battery post, 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 take the proper precautions could result in accidental airbag deployment.
On vehicles equipped with the high voltage system, disconnecting the 12 volt battery negative cable alone will not power down the 12 volt system. You must perform the 12 volt Power Down procedure before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
The hard wired circuits between components related to the Battery Electric Vehicle (BEV) telematics system Telematics Control Unit (TCU) 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 electronic controls and communication between the TCU and other modules or devices that provide some features of the BEV telematics system. The most reliable, efficient and accurate means to diagnose the electronic controls and communication related to BEV telematics system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information. Refer to UNIT, TELEMATICS CONTROL, DIAGNOSIS AND TESTING .