ABS and Traction Control System PDF

Anti-Lock Brakes, Traction Control, and Stability Control system PREPARED BY:-FUAD IBRAHIM  Contents o Anti-lock brake systems (ABS) o Traction and stability control systems o ABS service o Traction and stability control system service o Final system check ...

Anti-Lock Brakes, Traction Control, and Stability Control system PREPARED BY:-FUAD IBRAHIM  Contents o Anti-lock brake systems (ABS) o Traction and stability control systems o ABS service o Traction and stability control system service o Final system check  Unit one Introduction to Electronic Brake System  WHAT IS AN ANTI-LOCK BRAKE SYSTEM? An anti-lock brake system, ABS, is a system which is designed to prevent you from “locking” up your brakes, or applying so much pressure to your brakes that the axle and your wheels themselves stop turning completely. When your wheels stop turning but your car is still moving too fast, you start to skid, and skidding causes you to lose total control over your vehicle, which is a dangerous prospect when traveling at high speeds.  THE BENEFITS: The Antilock brake system is designed to prevent the brakes from locking up and skidding when braking hard or when braking on wet or slick surfaces. Antilock brakes do not necessarily reduce the stopping distance on dry surface, in fact may actually increase. But on wet or slick surfaces, antilock brakes may reduce the stopping distance up to 25% or more, which could be the difference between a safe stop or an accident. The ABS system has the ability to control wheel lockup during hard braking.  CONT.. A tire that is just on the verge of slipping (10 to 20% slippage) produces more friction to the road than one which is locked and skidding (100% slippage). Once the traction is lost, friction is reduced, the tire skids and the vehicle takes longer to stop. The only exception to this is when a tire is on loose snow. A wedge of snow will build up ahead of the locked tire which allows it to stop in a shorter distance than a rolling tire. That is why some vehicles have an on/off switch for deactivating the antilock system when driving on snow.  ABS Operation oFor maximum braking and control, extreme tire slip must be avoided oWhen the tire slips, its friction with the road surface drops and stopping distance increases oABS modulates braking effort at the controlled wheels to reduce the stopping distance and increase directional stability when braking  Why wheels lock during braking? oBrakes work to slow or stop a vehicle by utilizing two types of resistances. oResistance at the brake and oResistance between the road and tire oWhen resistance at the brake < resistance between the road and tire (with in 10 -30 % slip ratio)- braking can be controlled in a stable manner oWhen resistance at the brake > resistance between the road and tire – the tires will lock up and slip and the vehicle will begin skidding  CONT. o Moving Vehicles possess Kinetic Energy. o Brakes convert the kinetic energy into heat by g rubbing a disk pad against a disk (in a disc brake) or brake shoe against brake drum (in a drum brake). o Maximum deceleration is achieved when maximum energy maximum energy o conversion is taking place in the braking system. o This conversion is less efficient when a tire is skidding.  CONT. When the tires skid: – Braking distance increases  Steering control is lost Tire wear will be abnormal  CONT. During a skid the stopping distance is increased because the adhesion between a skidding wheel and the road is less than that given by a wheel that is on the verge of skidding. This is achieve achieved by the use of ABS (Anti-Lock Braking System), which prevent the road wheels locking wheels locking (by sensing a locked wheel, releasing it momentarily and re-applying it).  Why ABS? o For maximum braking and control, extreme tire slip must be avoided o When the tire slips, its friction with the road surface drops and stopping distance increases o ABS modulates braking effort at the controlled wheels to reduce the stopping distance and increase directional stability when braking CONT.  BASIC ABS COMPONENTS Antilock systems basically consist of: Wheel speed sensors ABS actuator ABS Control Module ABS Warning Light  Wheel Speed Sensors Produce ac signals that correspond to wheel and tire speed These signals are fed to the anti- lock brake system control module As the tire rotates, moving teeth on the sensor rotor induce current in the sensor winding  Sensor Signal Frequency A rapid decrease in a sensor’s signal frequency indicates that a tire is starting to lose traction and lock up The control module then sends an electrical signal to the hydraulic modulator to pulsate hydraulic pressure to the affected wheel brake, modulating braking effort  ABS ECU Uses wheel speed sensor inputs to control the ABS actuators ABS works in a closed loop with a series of inputs and outputs The most important inputs are from the wheel speed sensors The main output is brake system pressure control brake system pressure control by the ECU commands The ECU compares the signals from each of the wheel sensors and measures the acceleration or deceleration of an individual wheel  ABS actuator Regulates (modulates) the fluid pressure applied to each wheel brake assembly during ABS operation Controlled by the ABS ECU Pressure modulation refers to the rapid cycling of pressure to the brake assemblies, preventing wheel lockup occurs 15 to 20 times per second  Actuator Components Fluid reservoir and pump o for pressure reduction Solenoid valve block o computer-controlled valves that control brake fluid flow to the wheel brakes Master cylinder-booster assembly o conventional master cylinder and booster for normal braking  Modulator Components Fluid reservoir Hydraulic pump and motor holds an extra supply of brake motor-driven pump that provides brake fluid pressure for the system fluid Pressure switch Solenoid valve block monitors system pressure and controls the operation of the motor-driven pump computer-controlled valves Master cylinder-booster assembly that control brake fluid flow conventional master cylinder and to the wheel brakes booster for normal braking Accumulator chamber for storing fluid under high pressure  ABS Warning Light An ABS indicator light on your dash is a sign that something may have gone wrong with your system and you need to get it checked out. The four common reasons that typically cause this light to turn on include a malfunctioning ABS module, low levels in the fluid reservoir, broken wheel speed sensors, or the system is turned off.  FOUR REASONS YOUR ANTI-LOCK BRAKE SYSTEM LIGHT CAN COME ON Malfunctioning ABS Module Your ABS actually shares some important components with another system in your vehicle: your traction control system. Traction control is a system designed to keep all four wheels on the ground rolling smoothly. If it detects that one wheel starts to spin irregularly, it will cut off power from your engine until it establishes stable traction again.  CONT.… This is designed to prevent you from skidding out of control by accidentally applying too much power. However, because both your ABS and traction control share a control module and self-diagnostic system, one can sometimes interfere with another. Sometimes an issue with your traction control light can cause your ABS light to come on as well, but other times the issue is with your ABS system. You’ll need to have your vehicle professionally diagnosed to figure out exactly what’s going on.  LOW LEVELS IN THE FLUID RESERVOIR Your brake system is hydraulic, which means it uses the power of a cylinder pressing against a fluid to close your brake pads and bring your car to a stop. This means you need a consistent, constant level of fluid in your brake system. However, if there’s a slow leak or the fluid is able to evaporate off, then the amount of fluid will drop and your brakes won’t be able to operate properly. Your computer can usually detect this with sensors, and will turn the ABS light on if it finds it.  BROKEN WHEEL SPEED SENSORS Wheel speed sensors are a piece of equipment that tells your computer how fast each wheel is turning independently. If the computer detects an irregularity in these speeds, then your traction control system makes adjustments or shifts power to different wheels to compensate. However, if a speed sensor is dirty or stops working, then it can’t relay this information accurately. Rather than make a load of adjustments, it will usually disable your ABS and/or traction control systems until you either restart your vehicle or the problem gets resolved. YOUR SYSTEM IS TURNED OFF It may come as a surprise, but you actually may have the option to turn your traction control or ABS on and off. When you turn the system off, it will usually turn on the indicator light on your dash to warn you that this important safety feature isn’t working. If just your traction control or ABS light is on, then there’s a strong chance your system may have accidentally turned off. Check to see if you may have accidentally bump the switch, and consult your owner’s manual if you’re not sure where it is. block circuit diagram of ABS system  ABS Modes of Operation How the system works: The antilock braking system controls braking force by controlling the hydraulic pressure of the braking system, so that the wheels do not lock during braking. The system is essentially an "add-on" to the existing brake system. It only comes into play when traction is lost or during sudden stops. Otherwise it has no effect on normal driving or braking. THREE MODES OF ABS OPERATION ARE USED: normal braking mode Pressure reduction mode holding mode Pressure increase mode  Normal Braking Master cylinder pressure flows normally to the brake assembly No pump or solenoid operation occurs The ABS system is not functioning during normal driving The ABS system only became active during tire slippage.  Normal Braking During normal braking, as the rotation speed of the wheel drops, no current flows from the ECU to the hydraulic unit which the solenoid valve is not energized. The brake master cylinder hydraulic pressure is applied to the brakes, and the ABS is not involved. However, even the ABS is bypassed during normal braking, it's control module is constantly monitoring for sudden deceleration on any of the wheels.  Isolation Mode (Pressure holding) If a speed sensor senses deceleration of the wheels - which the wheel is most likely to lock up - the ECU sends a current to the hydraulic unit. This energizes the solenoid valve. The valve blocks the brake circuit from the master cylinder. This stops the braking hydraulic pressure at that wheel from rising, and keeps it constant (Hold pressure).  Isolation Mode (Pressure holding) The control module detects that a tire is starting to slip The module energizes a modulator solenoid to isolate that hydraulic circuit from the other brake lines Solenoid is energized with 1.9- 2.3 Amp The fluid is trapped in the wheel brake at the current apply pressure  Dump Mode (Pressure reduction ) If the sensors sense the wheel is still decelerating too rapidly, the ECU sends a larger current to the hydraulic unit. The outlet valve opens a passage and brake fluid is now sent back to the master cylinder. Pressure in the brake caliper is reduced so that the wheel is braked less heavily. (release pressure)  Dump Mode (Pressure reduction ) The control module detects that the tire is continuing to slip and slow down The module energizes a solenoid to release the fluid pressure from the wheel brake assembly to reduce braking effort Solenoid energizes with 4.5-5.7 Amp. The tire speed will tend to increase  Pressure increase(Reapply Mode ) f the wheel sensors indicate that decreasing the brake pressure is letting the wheel accelerate again, the ECU will stop sending current to the hydraulic unit and de- energizes the solenoid valve. This causes the brake pressure increases and the wheel again decelerated.  Pressure increase(Reapply Mode ) The control module detects that the tire speed has increased, so more braking is required The module de-energizes the solenoid solenoid and isolation solenoid to allow fluid pressure to build in the brake circuit again, restoring braking effort  DIFFERENT TYPES OF ABS SYSTEM: Each wheel of the vehicle is equipped with its own speed sensor. This type of system called a "four wheel, four channel" system since each wheel speed sensor would give its input into a separate circuit ( "channel" refers to each individual electronic circuit). A four-wheel ABS system which have a separate wheel speed sensor for each front wheel but use only one speed sensor for both rear wheels is called "three channel" system. The rear wheel speed sensor is mounted in either the differential or the transmission. The sensor reads the combined or average speed of both rear wheels. This type of setup saves the cost of an additional sensor and reduces the complexity of the system by allowing both rear wheels to be controlled simultaneously.  CONT.… Another type of system is called the "one-channel" system. This type of system is used on many rear- wheel drive pickups and vans. The front wheels have no speed sensors and only a single speed sensor mounted in the differential or transmission is used for both rear wheels. This Rear-wheel antilock systems are typically used on vehicles which their loading can affect the traction of the rear wheels. This is why it is used on pickup trucks and vans. Because the rear- wheel antilock systems have only a single channel, they are much less complex and costly than their three- and four-channel type system. CONT.…  Integrated ABS Combines the power booster, master cylinder, and modulator units into one assembly Most common on early systems Most expensive and difficult to repair  Nonintegrated ABS Major units are separated Uses a conventional master cylinder and booster The electro-hydraulic modulator is a separate unit Most common on recent ABS units  THE DRAWBACK The drawback to this particular ABS system is that because the rear wheels share one valve and speed sensor, they are monitored together. Therefore, both wheels must become locked in order to trigger ABS. If only one rear wheel locks, the brake’s effectiveness will be reduced.  THE DRAWBACK Like three-channel, three-sensor ABS, this system also carries the risk of one rear wheel locking, and thus lowering the effectiveness of the brakes. It is fairly easy to spot this system on a vehicle because there will only be one brake line that runs to the rear wheels through a T- fitting.  ADVANTAGES OF ANTI-LOCK BRAKES Shorter stopping distances: Anti-lock brakes reduce braking distances as the wheel does not waste distance skidding. Stopping on wet surface: ABS avoids wheel lock up and hence allows surefooted braking on wet sleety surfaces. Steer under braking: Anti lock brakes allow you to steer your car around objects if any as you still have grip on the wheels under intense braking. ADVANTAGES OF ANTI-LOCK BRAKES oGreatly reduce the possibility of brake lock up. Provide better chance of steering. Highly adaptable to every surface. Greatly reduces the possibility of vehicle skidding. Faster reactions to situations because of completely electronic & computer controlled.  DISADVANTAGES OF ANTI-LOCK BRAKES The primary disadvantage of ABS brakes is the increased cost it adds to the overall cost of a vehicle. Also maintenance costs go up as the sensors on each wheel are expensive and get heavy on the pocket if they run out of calibration. The job of anti-lock brakes is to provide sure footed braking. But this also has a side effect that is the inconsistent stopping distances on various surfaces under variable conditions. Also a reason for concern is that these electronic systems are quiet delicate and adding more mechanics to your car increases the possibilities of system damages.  DISADVANTAGES OF ANTI- LOCK BRAKES Expensive repairs & high cost of operation. Require regular check ups & maintenance of sensors, valves and brake fluid. Require complete overhaul on damage of few parts. Delicate system, easy to harm and damage. Longer stopping distances due to system errors.  ABS PROBLEMS A vehicle’s ABS control module is designed to notify the driver with a warning light if there is a malfunction in the system. Rarely is a malfunction the module or ABS itself. It is often one or more sensors, or the wiring to the sensors. The most common ABS problems occur when sensors b Malfunctions also occur when sensor wiring becomes damaged, resulting in intermittent or no continuity.  CONT.… In more corrosive environments or serious brake system neglect, brake fluid can become contaminated and the hydraulic control unit fails to function. become contaminated with debris or metal shavings. If you have a malfunction in the ABS, physically check all wiring and the brake sensors first. When checking the brake sensors, look for metal shavings and other debris that could cause false feedback to the electronic ABS controller. False feedback causes the ABS to trigger when it shouldn’t, or not function when it should. You may not have an ABS scan tool at home, but any reputable repair shop will have one, and the scan tool is invaluable if you can’t find a physical reason for your ABS issues. After the scan tool produces a fault code, you can proceed with your ABS troubleshooting. Whatever the problem, the repair is much easier once a fault is established. ABS Operation(Failure Mode) The ABS control unit monitors the pressure in the high-pressure passage When the pressure drops, the control unit turns on the ABS warning light The sleeve moves and hydraulically locks the back pressure chamber The master cylinder is connected to the caliper for normal braking  Unit Two Traction and Electronic Stability Control System  WHAT IS TRACTION CONTROL? Traction control is an active safety feature that helps to keep traction between the tires and the road in slippery or dangerous conditions. The safety feature maintains a car’s traction by limiting how much the wheels can spin, making it easier to stay connected to the surface you’re driving on. Since 2012, traction control is a standard safety feature on cars sold in the United States. While it can be turned on and off whenever the driver desires, there are few instances where it needs to be turned off. It is much safer to leave it on when possible.  Traction Control Systems The traction control system (TCS) helps a driver maintain control and stability of the vehicle if it loses grip and starts to skid or slide. The TCS automatically senses when a wheel loses traction at any time and can be triggered automatically as soon as this is detected. Loss of traction most commonly occurs in ice or snow, so the TCS shifts power from the wheel that is slipping to the wheels that are still gripping the pavement well.  Traction Control Systems Designed to prevent the vehicle’s wheels from spinning and losing traction under hard acceleration Most systems work with the anti-lock brake system to cycle hydraulic pressure to the wheel spinning the fastest The control module is capable of applying only one wheel brake at a time Some systems also reduce the engine’s power output to reduce slipping The indicator light is illuminated anytime the traction control system is activated warns the driver that the tires are losing traction  TRACTION CONTROL: HOW IT WORKS AND WHEN TO USE IT Driving at night during a rain or snowstorm can be a scary feeling, especially when you have to worry about your car losing traction, hydroplaning, or worse, potentially crashing. Traction also comes into play if you’re driving around a steep curve or on icy roads. Those conditions could significantly impact the traction of your tires. While nearly every car has an anti-lock braking system (ABS) light that comes on to notify you when you are losing traction.  Traction Control Systems Your traction control system lets you know it’s working and not working when the TCS light turns on. If the light comes on when it’s supposed to, it means it’s safe to drive with the TCS light on; if it doesn't, it means it’s not safe. Determine whether its safe to drive by understanding these 3 reasons your TCS light may come on:  CONT. is it safe in this situation? Yes. The most important thing to remember here is that the TCS light coming on, and often flickering on and off while it's activated, means the system is functioning properly. You should still drive with caution on wet or slippery roads, but seeing the light in these circumstances indicates your traction control system is working.  1. TEMPORARY LOSS OF TRACTION Some TCS lights come on when there is rainy or snowy weather and then disappear. When this happens, it means the system is activated due to low- traction road conditions (ice, snow, or rain) and is assisting the vehicle with maintaining traction. It may even flash briefly if you momentarily pass over a slick spot on the road. TCS intervention can be so understated you might barely notice it. It is a good idea to read the owner’s manual that came with your car to ensure you know how your TCS works and to know what to expect in these conditions.  2. FAULTY WHEEL SPEED SENSOR A set of wheel speed sensors at each wheel control the TCS and ABS (anti-lock brake system) to let your traction control computer know whether or not each wheel is rolling correctly or slipping in any way. Should the sensor detect slippage, it activates the TCS to reduce power to the affected wheel to let it regain traction, causing the light will engage for a short time.  CONT. A failing wheel speed sensor, or damages in its wiring, disrupts the connection between the wheel and TCS computer. This prevents the TCS working on that wheel, so the light will illuminate and stay lit until addressed. It may even turn on a “TCS off” light to indicate the system is not functioning.  CONT. Is it safe in this situation? No. If the light comes on, and you obviously have traction, it is safe enough to drive yourself to place to get an inspection of the light. However, a mechanic should check the TCS as soon as possible. A lingering or flickering light tends to mean the TCS is not working. Should you encounter adverse road conditions, the system will not engage and you face potential damage to the vehicle and yourself.  3. FAILURE OF TCS COMPUTER Controlling the actual system, the TCS computer has a vital role in proper traction control function. The whole system can go offline should corroded contacts, water damage, or malfunctions occur. This will activate the TCS light, and potentially the ABS light as well.  CONT. Is it Safe in this Situation? No. Like having a faulty wheel speed sensor, a failing TCS computer disallows the information about wheel traction to be acted upon. The system will not engage when it needs to. Again, drive carefully to a location where service can be requested and performed.  IS IT SAFE TO DRIVE WITH THE TCS LIGHT ON? It is only safe to drive with the TCS light on if it appears when you are losing traction: it means the system is engaging. Driving without traction control can make your vehicle susceptible to spinning out and sliding around on the road. It is best to keep your TCS in working condition and enabled in case hazardous weather pops up. This allows you to maintain control of your vehicle at all times.  CONT. Driving with your TCS Light on can be dangerous. You increase the potential of losing control of your vehicle. The TCS helps control the stability and traction of your vehicle, so without it, the vehicle may not handle slick roadways as it should. If your TCS Light remains on, your safest course of action is to have a certified mechanic perform a system inspection and TCS module replacement if necessary.  HOW DOES TRACTION CONTROL WORK? Traction control is a pretty simple concept, yet it is very effective. It is a system that has active sensors in each of your four tires, called yaw sensors. The sensors monitor each of your tries. While monitoring, the sensors keep a careful eye on both the speed of the vehicle and what the tires are doing. If any of the tires spin faster than what speed the car is going, that tire will begin to lose traction — which could lead to skidding or hydroplaning. This is where traction control steps in to avoid either from happening.  HOW DOES TRACTION CONTROL WORK? Works in the background to help accelerate and prevent wheel slippage (or “over-spinning”) when driving on slippery surfaces. Traction control is most effective when accelerating from a stopped or slowed position, or when trying to accelerate up a slippery hill. This feature provides a lot of benefits to drivers, from making driving smoother to helping them stay in control of the car on icy roads or during rainy weather. Drivers should be sure to reduce their speed and take turns more slowly when driving in slippery conditions.  Helps your wheels gain traction on slippery surfaces. Does not work as well as snow tires. 1. Increases Traction Helps prevent wheels from spinning on slippery surfaces And increases traction when accelerating.  2. ENGAGE Traction Control will only engage when your wheels start to slip.  3. WHEN TO TURN OFF Turn off Traction Control if stuck in mud or snow and need to rock the car Or when using tire chains.  Unit Three Servicing and Repairing Electronic Brake System, Traction & Stability System  WHAT HAPPENS WHEN I PRESS MY TRACTION CONTROL BUTTON? When turned off, you may notice that your vehicle handles differently than you are used to when driving on slippery surfaces. This is why you should leave your traction control on at all times.  WHY WOULD I EVER NEED TO TURN OFF MY TRACTION CONTROL? You should leave your traction control at all times so that you can benefit from this important safety feature. However, in very rare circumstances, you may need to turn the traction control off temporarily. These include the following: You are driving in a region that requires your tires to have chains, and your vehicle’s traction control is interfering with your ability to drive. Your car is trapped in very deep snow, mud or other surface in which your car cannot move out on its own. Turning off traction control while you rock your car may help you drive out faster.  WHAT IS AN AUTOMATIC TIRE CHAIN SYSTEM? The physical function of On spot can be described as simply utilizing a wheel fitted with chains in place of wrapping traditional chains around the tire. The chain wheel, as we call it, is guided and held to the inside of the tire where centrifugal force allows the individual chain strands to extend beneath the drive wheel. On spot matches the function of traditional tire chains without the need to exit the cab to install them. On spot is designed to be permanently mounted to each specific vehicle and is activated by the use of a dashboard switch.  WHAT ARE COMMON SYMPTOMS INDICATING YOU NEED TO FIX THE TRACTION CONTROL SYSTEM? TSC dashboard light goes on Traction control system won’t turn on or off Loss of traction control features Loss of the anti-lock brake system  KEEP IN MIND The traction control system indicator light can mean many different things. It’s important to find out why the light is on and determine if it is a simple fix or if it needs a more significant repair. Since the traction control system and the ABS work together, you should also have the ABS checked while fixing the TCS.  HOW TO FIX THE TRACTION CONTROL SYSTEM There are numerous components to the traction control system, so properly diagnosing the issue is crucial in saving time and money. A faulty traction control module is one of the most common problems with the traction control system. You can replace the module in a few steps, but you’ll first need to purchase a new module or you can usually find quality control units in low-mileage. Make sure to research the one you need for your vehicle’s make and model.  STEP 1: DISCONNECT THE BATTERY Whenever you work on electronic components in your vehicle, disconnect the battery, starting with the negative cable. You’ll need a wrench to loosen the nut in order to remove the cables. Once you have the negative cable off, you can remove the positive cable.  STEP 2: LOCATE THE TRACTION CONTROL MODULE Depending on the vehicle, it might be under the hood as a part of the ABS control module. For other vehicles, it could be in the trunk area or toward the interior of the vehicle. STEP 3: DISCONNECT THE TRACTION CONTROL MODULE Unplug the electrical connectors. Be sure to take pictures along the way, or use masking tape to label all connections, so you can put everything back together correctly. Remove the screws that hold the module in place.  4: CONNECT THE NEW MODULE Put the new module in the place of the old one and connect all the wiring and connectors that you unplugged from the original part. If you have an older vehicle, be careful with the plastic connectors because plastic can get brittle and break easily.  STEP 5: START THE VEHICLE Reconnect the negative battery terminal and start up your vehicle. Watch for the ABS and check engine light will illuminate briefly and then go out. If the traction control system light is still on, it might take a few ignition cycles to clear any codes that are stored in the system.  ELECTRONIC STABILITY CONTROL What is Electronic Stability Control? Electronic Stability Control (ESC) is an active safety system that reduces the risk of a driver losing control of the vehicle when it skids, change direction suddenly or when road conditions change. ESC builds upon features such as Anti-lock Braking Systems (ABS) and traction control to stabilize the vehicle when it deviates from the driver’s steered direction.  ELECTRONIC STABILITY CONTROL It is an intelligent safety system that can predict driving intentions. Firstly, the ESP helps the driver to maintain the wheel trajectory. However, it does so by applying brakes to the individual wheels. Secondly, it can also adjust the engine performance in critical maneuvers. However, the ultimate purpose of the ESP is to enhance vehicle stability. Thus, ESP improves stability by avoiding skidding.  ELECTRONIC STABILITY CONTROL ESC considerably reduces the risk of single vehicle crashes by: Correcting impending over steering or under steering Stabilizing the vehicle during sudden evasive maneuvers e.g. swerving Improving handling on gravel roads e.g. road shoulders Improving traction on slippery or icy roads. Helps prevent loss of control in curves and emergency steering maneuvers by stabilizing your car when it begins to veer off your intended path.  DIFFERENT MANUFACTURERS CALL ESC BY DIFFERENT NAMES , some include: Electronic Stability Program (ESP) Dynamic Stability Control (DSC) Vehicle Dynamic Control (VDC) Vehicle Stability Control (VSC) Dynamic Stability & Traction Control (DSTC) Active Stability & Traction Control (ASTC)  ESP COMPONENTS The Electronic Stability Program consists of the following components which are: 1. Hydraulic Unit 2. Wheel speed sensors 3. Steering angle sensor 4. Yaw rate and lateral acceleration sensor 5. Engine Control Unit  HOW DOES IT WORK? Using a number of intelligent sensors, ESC immediately identifies when a car has deviated from the driver’s steered direction and the driver has lost control of the vehicle. As soon as impending instability, over steering or under steering are registered, ESC stabilizes the vehicle by selectively braking individual wheels and reducing engine torque to bring it back on course movements.  HOW DOES IT WORK? ESC uses components of ABS and traction control to stabilize the vehicle, but unlike ABS and traction control which only operate in the driving direction, ESC also helps the driver control sideways movements which create instability. This makes ESC a total, holistic system that controls a car’s entire 1. ACTIVATE Electronic stability control (ESC) activates when you start your car. 2. USE ESC engages automatically to help prevent over steering and under steering. 3. STAY ON PATH ESC works by braking individual wheels and reducing engine speed - helping you maintain control.  WHAT IT DOES This feature helps prevent you from losing control of the direction of your car due to a spin out or plow out. When effective, this also significantly reduces your risk of being in a rollover – one of the most dangerous types of single- vehicle crashes.  THE TECHNOLOGY BEHIND IT A series of sensors read the direction your vehicle is going, the position on your steering wheel and the brakes on your tires. If they detect that the car isn’t going in the direction you intended it to go, this feature helps correct your car back on- route by adjusting your speed and selectively braking one or more wheels. Without ESC, as this image shows, you may depart the road or get into a crash.  WHAT YOU NEED TO DO Spin outs and plow outs most often occur when you are taking turns too sharply and quickly; and when you make sudden maneuvers on slippery roads. You should always be sure to take turns slowly and carefully – which may require you to reduce your speed – and adjust your following distance on slippery roads so that you can brake or steer to safety sooner when needed.  WHAT DO I DO IF MY ESC IS MALFUNCTIONING? Electronic stability control works most effectively when your car’s anti- lock braking system is working effectively. ESC relies on the anti-lock braking system (ABS) and the traction control systems to function; if one or both of those systems are not operating correctly, ESC is unable to help stabilize your car in emergencies. If you are receiving an ESC malfunctioning icon, it may mean there is something wrong with your ABS, traction control or your ESC system directly.  CONT. If you are having problems with your ABS, your ESC may not work well or at all. Common causes of 4-wheel ABS malfunctions include worn brake linings and air or dirt in the brake fluid. Both ESC and ABS work most effectively when the tires are properly inflated and in good condition.  WHAT DOES THE ESC LIGHT WARNING INDICATE? The simplest way to know why your ESC light is on is to take it to diagnosis. The technician uses a scanner to decode trouble codes from the brake control module, and within no time, you get to know what is ailing your car. However, before you get there, below are a few hints on what might be wrong:  WHAT DOES THE ESC LIGHT WARNING INDICATE? Faulty Wheel Sensors Each of your car's wheels has sensors that communicate the loss of traction to the Electronic Stability Control system. When these sensors are covered in dirt, they cannot detect whatever is happening, leading to the ABS and ESC system's malfunctioning. Issues with The Wiring It is the wires that facilitate communication about traction from the wheel sensors to the onboard computers. If these wires happen to be broken, improperly connected, or the ESC fuse is blown, the warning light will not illuminate. A Malfunctioning Steering Angle Sensor If the steering angle sensor is faulty, misaligned, or damaged, the ESC warning light may be constantly on.  SYMPTOMS OF ELECTRONIC STABILITY CONTROL PROBLEMS Electronic Stability Control System / ESC light on -The electronic stability control light will illuminate when the car is unable to keep traction. If you see this light you should take care while driving, especially when turning sharp corners., Slippery driving – Your car’s steering may feel less responsive, especially when turning sharply. When this happens, be sure to take turns slowly. This will help you to keep control of your vehicle. Faulty ABS system/ABS light – Since the Electronic Stability Control System (ESC) system often uses ABS components, a faulty ABS system will often play a role in its failure. If the ABS light is on, there is likely a problem with your speed sensors, control module, ABS pump or relay. BRAKE-BY-WIRE SYSTEM  BRAKE-BY-WIRE SYSTEM Brake-by-wire systems insert electronics into the mechanism. In a car with brake-by-wire, pressing the brake pedal sends a signal to a brake control unit that then actuates the brakes. Computers determine, based on pedal position and pressure, how much braking the driver wants. An electric pump then pushes hydraulic fluid through brake lines, much like conventional braking systems.  BRAKE-BY-WIRE SYSTEM Brake-by-wire refers to the technology in which mechanical and hydraulic components of traditional braking systems are replaced by electronic sensors and actuators to carry out the function of braking in a vehicle. Brake-by-wire is a combination of electronic control systems coupled with a set of electromechanical actuators and a human- machine interface, which is in this case, the brake pedal. The use of brake-by-wire systems enumerate many benefits such as weight reduction and space saving, lower operating noises and vibrations, and quicker reaction time due to the absence of mechanical linkages, which would result in shorter stopping distances.  BRAKE-BY-WIRE SYSTEM However for successful application on an extensive basis, the wrinkles in the system's working need to be ironed out to devise a fail-safe version with a clear indication of its distinctive advantages over conventional braking systems, to warm vehicle manufacturers and consumers alike to the idea of its ubiquitous implementation in vehicles. Due to the safety critical nature of brake-by-wire systems, incorporating a degree of fault tolerance is vital. The most commonly suggested solution is a redundant or back-up brake system, such as a conventional hydraulic system, that would be brought into activation in the event that the primary system suffers a failure. BRAKE-BY-WIRE SYSTEM COMPONENTS  BRAKE-BY-WIRE SYSTEM A vehicle with brake-by-wire technology employs a set of actuators, most commonly powered by permanent magnet DC electric motors, near each wheel to produce the braking pressures. Each of the actuators is governed by electronic control units that are connected to the brake pedal. The driver's interaction with the brake pedal is converted to a set of electronic instructions, which are communicated throughout the braking system via a communication network, such as CAN (Controller Area Network) or Flex Ray. A series of sensors such as brake pedal position sensor, wheel speed sensors, steering angle sensor, yaw rate sensor and lateral acceleration sensors help in appropriate assessment of the situation and accordingly adjusts the braking pressure required.  Based on how hard or how far the driver pushes the brake pedal under different circumstances, the sensors transmits information to the ECU, which forms a picture of the mildness or urgency of the braking situation and proportionally decides the required braking pressure to be applied at each wheel. The system is also capable of increasing braking pressure on one side of the vehicle to amend under-steer or over-steer, or adjusting braking pressures on each wheel based on individual grip conditions. In addition, auxiliary systems like ABS, ESC and collision avoidance would work in cohesion with the brake-by-wire system to enhance overall safety and efficiency. With all these systems working in unison, the vehicle's safety is taken to the next level, compensating for driver error or delayed reaction times. THANK YOU!!!