Chart B-1 BCM Power and Grounds

CIRCUIT DESCRIPTION
The loss of BCM functions can result from the following:
^ Loss of +12 volt power (CKT 640) to the BCM.
^ Loss of ground (CKT 803) to the BCM.
^ Internal BCM fault.

TEST DESCRIPTION
Numbers below refer to circled numbers on the diagnostic chart.
1. The BCM is not receiving a +12 volt input therefore check the power and ground supply to the BCM.
2. This step checks for a short to ground in any of the 640 CKTs.
3. Checks to see if the short to ground is inside a component or in the circuit itself.