ABS solenoid- https://www.youtube.com/watch?v=-IUZWwMm7nY

What happens during normal braking?

• Electric current flows from the ECU to the hydraulic unit

• The solenoid valve is energized

• The brake master cylinder hydraulic pressure is applied to the brake unit

• The ABS control module is constantly monitoring for rapid deceleration

What does the ECU do if a wheel speed sensor signals severe wheel deceleration?

• Sends a current to the hydraulic unit

• Energizes the solenoid valve

• Opens a passage from the brake circuit

• Increases the brake pressure

What happens if the wheel sensors indicate that lowering the brake pressure is letting the wheel accelerate again?

• The ECU stops sending current to the hydraulic unit

• The solenoid valve is de-energized

• The pressure increases

• The wheel is decelerated

How many times does the cycle of changing brake pressure repeat per second in an ABS?

• 2 to 4 times

• 4 to 6 times

• 6 to 8 times

• 8 to 10 times

What may cause rapid pulsations to be felt through the brake pedal in an ABS?

• Changes in position of the valves and hydraulic control unit

• Decrease in brake pressure

• Increase in wheel acceleration

• Malfunctioning of the ECU