Brake system indicator does not come on

Brake system indicator does not come on
1. Turn the ignition switch ON (II), and watch the brake system indicator.
Does the brake system indicator come on and go off?
YES - The system is OK at this time.
NO - Go to step 2.
2. Check the DTCs using the HDS.
Is DTC 91 or 92 indicated?
YES - Troubleshoot the DTC indicated, and recheck.
NO - Go to step 3.
3. Do the gauge control module self-diagnosis function procedure.
Is the gauge control module OK?
YES - Go to step 4.
NO - Replace gauge control module.
4. Turn the ignition switch OFF.
5. Substitute a known-good VSA modulator-control unit.
6. Turn the ignition switch ON (II), and watch the brake system indicator.
Does the brake system indicator come on and then go off?
YES - Replace the original VSA modulator-control unit.
NO - Replace the gauge control module.