Nissan Sentra B18 (2020-2025) Service Manual: Brake Booster. Inspection
Inspection
BRAKE BOOSTER
Operation
Depress the brake pedal several times at five second intervals with the engine stopped. Start the engine with the brake pedal fully depressed. Check that the clearance between brake pedal and dash lower panel decreases.
Note: 
A slight impact with a small click may be felt on the pedal when the brake pedal is fully depressed. This is normal brake system operation.
Vacuum Inspection
Idle the engine for one minute to apply vacuum to the brake booster. Stop the engine. Depress the brake pedal several times at five second intervals until the accumulated vacuum is released to atmospheric pressure. Check that the clearance between brake pedal and dash lower panel gradually increases (A –>B –>C) each time the brake pedal is depressed during this operation.
Depress the brake pedal with the engine running. Then stop the engine while holding down the brake pedal. Check that the brake pedal stroke does not change after holding down the brake pedal for 30 seconds or more.
Note:
A slight impact with a small click may be felt on the pedal when the brake pedal is fully depressed. This is normal brake system operation.
Other materials:
C1155 BR Fluid level low
DTC Logic
Dtc detection logic
Dtc
Display item
Malfunction detected condition
Possible cause
C1155
C1155 br fluid level low
Brake fluid level is low or communication line between
the abs actuator and electric unit (control unit) and brake
fluid level switch is ...
Ecu diagnosis information
Ipdm e/r (intelligent power distribution module engine room)
Reference Value
Values on the diagnosis tool
Terminal layout
Physical values
Fail-Safe
Can communication control
When can communication with ecm and bcm is impossible, ipdm e/r performs
fail-safe ...
Warning signals
To help prevent the vehicle from moving unexpectedly
by erroneous operation of the Intelligent
Key or to help prevent the vehicle from being
stolen, a chime or buzzer sounds from inside and
outside the vehicle and a warning light comes on
in the instrument panel.
When a chime or beep sounds ...