Diagnosis And Testing - Body Control Module
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 Body Control Module (BCM) 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 BCM electronic controls or the communication between modules and other devices that provide some features of the BCM-controlled systems. The most reliable, efficient and accurate means to diagnose the BCM or the electronic controls and communication related to BCM-controlled systems operation requires the use of a diagnostic scan tool. Refer to DIAGNOSIS AND TESTING .