Unit 3: Braking System - Activity 4: Anti Lock Brake Basics

Read the passage below and answer the question: The anti lock brake system (ABS) is an electronically controlled brake system that prevents wheel lock up under extreme or emergency braking. The system is designed to prevent wheel lock up. Once wheels lock the vehicle goes into a skid and the driver loses traction and the ability to steer the vehicle. Before ABS systems were used on vehicles many drivers would pump the brake pedal quickly in emergency braking situations to prevent wheel lock up and skid situations. What is the main purpose of the anti lock brake system (ABS)?

• To increase vehicle speed

• To prevent wheel lock up

• To reduce fuel consumption

• To improve engine performance

Read the passage below and answer the question: The anti lock brake system (ABS) is an electronically controlled brake system that prevents wheel lock up under extreme or emergency braking. The system is designed to prevent wheel lock up. Once wheels lock the vehicle goes into a skid and the driver loses traction and the ability to steer the vehicle. Before ABS systems were used on vehicles many drivers would pump the brake pedal quickly in emergency braking situations to prevent wheel lock up and skid situations. True or False: The ABS helps the driver maintain the ability to steer the vehicle during emergency braking.

• True

• False

One of the main components of ABS is the ________.

• Electronic control Unit

• Fuel injector

• Radiator

• Clutch plate

Which of the following is NOT a main component of ABS?

• Electronic control Unit (ECU)

• Hydraulic Control Unit or modulator

• Wheel Speed Sensors

• Fuel Injector

Refer to the diagram of the ABS system. Which component is responsible for detecting the speed of the wheels?

• Power booster & master cylinder assembly

• Hydraulic control unit or modulator

• Wheel sensor unit

• Electronic control unit (ECU)

What is the main function of the ECU in a vehicle's braking system?

• To pump the brake pedal manually

• To receive input signals and determine the correct output command to the hydraulic control unit

• To control the speed of the car

• To illuminate the ABS light

When you start your car, what does the ECU do as part of the ABS system?

• It pumps the brakes

• It completes a self check of the ABS

• It turns off the engine

• It increases the speed

If the ABS light stays illuminated on the dash after the ECU self check, what does it indicate?

The Hydraulic Control Unit or Modulator uses solenoids controlled by the ECU to control valves that open and close to control when brake fluid pressure reaches the wheel cylinders or calipers.

• True

• False

How much faster can the hydraulic control unit simulate the pumping of the brake system compared to a human?

• 10 to 15 times faster than any human can pump the pedal.

• About the same speed as a human can pump the pedal.

• 2 times slower than a human can pump the pedal.

• 5 times faster than a human can pump the pedal.