Trouble Shooting: Notes

The hard-wired inputs to and outputs from the Body Control Module (BCM) may be diagnosed and tested using conventional diagnostic tools and procedures. Conventional diagnostic methods may not prove conclusive in the diagnosis of the BCM. In order to obtain conclusive testing of the BCM, the Programmable Communications Interface (PCI) data bus network and all of the electronic modules that provide inputs to or receive outputs from the BCM must also be checked. The most reliable, efficient, and accurate means to diagnose the BCM, the PCI data bus network, and the electronic modules that provide inputs to or receive outputs from the BCM requires the use of a DRBIII(R) scan tool and the appropriate diagnostic information. The DRBIII(R) scan tool can provide confirmation that the PCI data bus network is functional, that all of the modules are sending and receiving the proper messages over the PCI data bus, and that the BCM is receiving the proper hard wired inputs and responding with the proper hard wired outputs needed to perform its many functions.

Diagnosis of the body system is done in six basic steps:

1. Verification of complaint.
2. Verification of any related symptoms.
3. Symptom analysis.
4. Problem isolation.
5. Repair of isolated problem.
6. Verification of proper operation.