Brake Hold - freightliner M2 Plus 2023 Manual

HSA is on by default. It can be turned off by pressing
the HSA OFF dash switch shown in
04/18/2016
Fig. 7.6, Hill Start Aid Off Dash Switch
When hill start aid is inactive, the HSA OFF telltale,
shown in Fig. 7.7, flashes on the driver display
screen.
05/16/2022
Fig. 7.7, Hill Start Aid Disengaged Telltale
To turn hill start aid on again, press the HSA OFF
switch or cycle the vehicle keyswitch.
If the hill start aid disengaged telltale appears as a
solid image on the driver display screen, there is a
fault in the system.

Brake Hold

The brake hold function eases the strain of driving in
stop-and-go traffic by allowing the driver to "hold" the
brake without constantly applying pressure to the
brake pedal. The brake hold function is an extension
of hill start aid (HSA).
To activate the brake hold function, bring the vehicle
to a complete stop, then press the brake pedal
further toward the floor. The HOLD telltale, shown in
Fig. 7.8, illuminates on the driver display to indicate
the function is active and the vehicle's brake lights
come on. The driver can then take their foot off the
brake pedal without releasing the service brakes.
If the brake pedal is pressed down farther, air is
added to the chamber, continuing the brake hold.
Fig. 7.6.
HSA
OFF
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f611712a
Driver Assistance Features
03/18/2022
Fig. 7.8, Brake Hold Active Telltale
To release the brake hold, press the accelerator
pedal, engage the park brake, or rapidly apply and
release the brake pedal.
The hold function is deactivated when the HSA OFF
switch is pressed to disable HSA.
The hold function cannot be engaged if any of the
following are true:
•
the anti-lock braking system was active in
bringing the vehicle to a stop,
•
the anti-lock braking system is in a fault state,
or
•
the vehicle is in reverse gear.
If the hold function is active for four minutes, the
window shown in Fig. 7.9
warning the driver to engage the park brake. An
audible alarm activates at the same time and repeats
every minute until the park brake is set.
03/18/2022
Fig. 7.9, Engage Park Brake Message
The same warnings are triggered if the hold function
is active and:
•
the ignition is turned off without the park brake
being set, or
•
the brakes are not strong enough to hold the
vehicle in place and it starts rolling.
f612019
appears on the ICU
f612018
7.4