Volvo S90 2019 Owner's Manual page 429

Brake functions
The car's brakes are used to reduce the
speed or prevent the car from rolling.
In addition to the foot brake and parking
brake, the car is equipped with several auto-
matic brake assist functions. These can assist
the driver by not needing to keep his/her foot
on the brake pedal when at a traffic light, or
when starting on an uphill gradient.
Depending on the car's equipment, the follow-
ing auto braking functions are available:
Automatic brake when stationary (Auto
•
Hold)
Hill start assist (Hill Start Assist)
•
Auto braking after a collision
•
City Safety
•
Related information
Foot brake (p. 427)
•
Parking brake (p. 429)
•
Automatic braking when stationary
•
(p. 433)
Auto braking after a collision (p. 435)
•
Help when starting on a hill (p. 434)
•
City Safety™ (p. 294)
•
Anti-lock Braking System
2
Foot brake
The foot brake is part of the brake system.
The car is equipped with two brake circuits. If
a brake circuit is damaged, the brake pedal
may engage deeper. Higher pressure on the
pedal will therefore be needed to produce the
normal braking effect.
The driver's brake pedal pressure is assisted
by a brake servo.
WARNING
The brake servo only works when the
engine is running.
If the foot brake is used when the engine is
switched off then the pedal will feel stiff and a
higher pedal pressure must be used to brake
the car.
In very hilly terrain or when driving with a
heavy load the brakes can be relieved by using
engine braking in manual gearshift mode.
Engine braking is most efficiently used if the
same gear is used downhill as up.
Anti-lock braking system
The car has anti-lock brakes (ABS
prevents the wheels from locking while brak-
ing and allows maintained steering control.
Vibration may be felt in the brake pedal when
this is engaged and this is normal.
A short test of the ABS system is made auto-
matically after the car has been started when
the driver releases the brake pedal. A further
automatic test of the system may be made at
low speed. The test may be felt as pulses in
the brake pedal.
Symbols in the driver display
Symbol Specification
Check the brake fluid level. If the
level is low, fill with brake fluid
and check for the cause of the
brake fluid loss.
Constant glow for 2 seconds
when the engine is started: Auto-
matic function check.
Constant glow for more than 2
seconds: Fault in the ABS sys-
tem. The car's normal brake sys-
tem is still working, but without
the ABS function.
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STARTING AND DRIVING
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427