Alright, so it must be in the FSM instead...
But the Owner Manual says:
Brake warning light
This light functions for both the parking brake and
the foot brake systems.
When the ignition key is in the ON position, the
light comes on when the parking brake is applied,
and also warns of a low brake fluid level. If the
light comes on while the engine is running with
the parking brake not applied, stop the vehicle
and perform the following:
1. Check the brake fluid level. Add brake fluid
as necessary. See “Brake fluid” in the “Maintenance
and do-it-yourself” section of this
2. If the brake fluid level is correct, have the
brake system checked by a NISSAN dealer.