Chart B-1

You have been directed to this chart from the Self Diagnostic System Check" due to one or all of the displays blank. This could be caused by a BCM, Central Power Supply (CPS), Computer Control Driver Information Center (CCDIC), Instrument Panel Cluster (IPC), or power problem.

Notes on trouble trees
1. Brake application will determine if the BCM is able to
"Wake-Up" the CPS and communicate with the OSM's to turn on the brake lamps.
2. This step checks for Ignition-3 (I-3) input to the BCM. If I-3 is not at system voltage the BCM will not turn on the displays.
3. This checks the CPS for correct 12 volt output on circuit 812A.
4. Although the fuse is good, the CPS has no voltage, therefore there is an open in the supply to the fuse, or between the fuse and the CPS.
5. The fuse was blown, therefore replacing the fuse will determine if there is a current or intermittent circuit failure.

Notes on Intermittents
Check circuits 640, 812A, B and C for intermittent shorts to ground.