Chevrolet 2003 Silverado 1500 Pickup Owner's Manual page 219

REDUCED BRAKE POWER
If your vehicle has vacuum assist power brakes, this
message will be displayed and you may notice that the
brake pedal is harder to push and it will take longer
to stop. You may also hear a motor running and feel a
slight vibration in the brake pedal or steering wheel
when you apply or release the brake pedal even if your
foot is not on the brake pedal. This indicates that the
Supplemental Brake Assist system is working to
maintain braking power. If you are braking lightly, you
may not notice any difference in the operation of
your brakes.
This message may also be displayed for brief periods if
you are driving at higher elevations and are pumping
your brakes or braking hard. The message may
clear after you've lifted your foot from the accelerator
pedal an allowed the vehicle to coast in gear or after you
have driven down to a lower elevation. This is a
normal operation of your brake system and does not
require that the brake system be serviced. However, if
the message does not clear, your brake system
needs service. While the message is displayed you will
notice that the brake pedal is harder to push and it
will take longer to stop. See Brake System Warning
Light on page 3-40.
Your brake system may not be working
properly if the REDUCED BRAKE POWER
message is displayed. If this message comes
on and stays on while driving, pull off the road
and stop carefully. The brake pedal will be
harder to push and it will take longer to stop.
If the message is no longer displayed after you
have pulled off the road and stopped, you can
continue driving.
However, if the message is still displayed, or if
it comes on again when you are driving, there
continue to drive with this message displayed
it can lead to an accident. You should have the
vehicle towed for service. Also, see Brake
System Warning Light in the Index.
~
is a problem with your brake system. If you
3-64