Honda 1991 Accord Sedan, Owner'S Manual, Page: 19 / 146

Anti-lock Brake System (SE)
Anti-lock brake system helps to maintain the road holding and
tractability of your car during severe braking, and under slippery
road conditions. The Anti-lock brake system provides assistance to
help prevent the wheels from locking (thus reducing the chance of
skidding) to ensure controllable deceleration. When sudden braking
might otherwise lock one or more wheels, the Anti-lock brake
system temporarily reduces the braking pressure to the wheel or
wheels about to lock to ensure continued braking efficiency.
When the Anti-lock brake system is regulating the braking pressure,
the brake pedal pulsates slightly to make the driver aware that the
system is compensating for critical braking conditions. The pulsating
brake pedal can be an indication of hazardous road conditions, and a
reminder for you to take extra care. Under such conditions, you
should continue braking hard without pumping the brake.
Don't mix different diameter tires; it will confuse the Anti-lock
brake system computer which monitors the road speed of each
wheel. For example, if one or more tires are larger than the
others, the computer will think they are rolling more slowly (as if
they are about to lock-up) and reduce brake pressure to those
wheels.
On loose or uneven surfaces (gravel, ruts etc.) where all four
wheels lose traction intermittently, the Anti-lock brake system
may require a longer stopping distance than an equivalent car
with a conventional braking system.
The Anti-lock brake system cannot make up for extreme road
conditions or driver misjudgement. It is still the driver's
responsibility to drive at a suitable speed and provide a margin
of safety for the road, weather and traffic conditions at hand.
CAUTION:
Be careful not to damage the wiring or the speed sensors at the
back of each wheel when removing mud or snow from the wheel
housings.
NOTE:
You may hear a sound like a small motor running, coming from the
engine while driving or after the Anti-lock brake system is applied.
This indicates the Anti-lock brake system pump is in service and the
system is working properly.