Brake System Indicator Does Not Come ON

Brake system indicator does not come on for bulb check after the ignition switch is turned ON, and the parking brake switch and brake fluid reservoir switch are open.
1. Disconnect the multiplex control unit 13P (underdash fuse/relay box Y) connector and the ABS control unit 47P connector.
2. Check for continuity between the ABS control unit 47P connector terminal No. 13 and body ground.
Is there continuity?
YES - Repair short to body ground in the wire between the multiplex control unit and the ABS control unites
NO - Do the multiplex control system troubleshooting.