B-1 Displays Blank

Chart B-1:

CPS Circuit Detail:

DESCRIPTION:

You have been directed to this chart from Chart B due to one or all displays being blank and the brake lamps do not work. This chart will determine why the BCM and CPS are not Awake and not able to function.

NOTES ON FAULT TREE:

1. It has been determined that the BCM has the correct conditioned 12 volt input. This checks for proper 7 volt inputs.

2. With the key on in the run position, there should be no crank input to the BCM. If the crank input remains high the BCM and other components will not wake up, resulting in blank displays.

3. With the key in the run position, the BCM should wake up the CPS with a greater than 10 volt signal to the CPS on circuit 555. If the voltage is there, the problem must be a poor connection at the CPS. If there is no voltage, then the wire or BCM are suspect.