Technical Car Experts Answers everything you need: wheel speed sensor

Thursday, November 17, 2011

How Anti-Lock Brakes Work?

Anti lock brake system,its also known as ABS.There are many types/brands of ABS system in market.But basic working procedure is same for All ABS systems.Bosch ABS systems are very famous and well known for its good results.
If you choose between normal braking and ABS brake systems then ABS is par better system.Due to its braking ability and other additional functions included in ABS system.

This brake systems reduces the risk of accidents.This brake system maintain control and directional stability of vehicle in case of emergency braking requirements. It controls the rotational speed of every wheel by metering the brake line pressure while extreme braking.

Previous brake systems only use to help in slowing and stopping the vehicle.But ABS provide non-skid functionality including it also supports electronic stability control, brake assist, traction control, brake warning indicators etc etc . On modern latest cars they have included two new sensors.They are gyroscopic sensors and steering wheel angle sensors. This sensors help to match the direction of the car with the direction of the steering wheel. One more benefit of wheel angle sensor is that it supports the ABS system to control the outer wheels to have a more positive braking effect when compared to the inner wheels on road curves while driving.

ABS system consists of central electronic unit, four solenoid valves and two or more electric hydraulic pumps.This all parts makes ABS system work.If any of this part fails,the ABS system problem will be noticed.
The working procedure of this ABS system parts is very simple.
Hydraulic pump supplies brake fluid.It supplies this brake fluid pressure to the braking system by forcing hydraulic pressure to a reservoir.The reservoir is located in the accumulator. The 4 solenoid valves are used to control brake fluid pressure for each wheel.
Each wheel has its own wheel speed sensors.Exact location of wheel speed sensor may vary on all brand vehicles.Its mentioned in your cars service manual.But in most cars the front sensor is located towards front wheel hub or CV joints and rear wheel sensor is located towards rear driver assembly on the ring gear.

This ABS system is all controlled by computer.There is a module that controls the ABS system.This module is called ABS module.This ABS module is connected to main computer of the car.This main computer of car is called ECM or ECU.It means engine control module or engine control unit.
When you notice problems with ABS system.You will get warning indicator on DASH.The ABS light will illuminate.In that case,you need to get your ABS module scanned.There will be error code stored in your ABS module.This module can be scanned by scan tool if you have one or you can get it scanned by proper auto parts store.In scanning procedure,the device will show you error codes.As per error codes,it will point out towards the parts to be checked.So you can carry on your troubleshooting as per that.Get that parts checked and repaired or replaced,as per requirement.

This procedure will help you to understand your cars ABS system and its working procedure.

Thanks.

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