With the advent of a new brake system Improved vehicle safety during emergency braking. The system began to be installed in the 70s. IN ABS system includes a control unit, hydraulic unit, wheel brakes and speed sensors.
The main device of the ABS is the control unit. It is he who receives signals from touch sensors in the form of the number of wheel revolutions and evaluates them. The data obtained is analyzed and the system draws a conclusion about the degree of wheel slip, their deceleration or acceleration. The processed information is sent in the form of signals to the magnetic valves of the hydraulic unit, which performs the control task.
Pressure is supplied from the master brake cylinder (MBC), which ensures the appearance of pressing force in brake cylinders calipers. Thanks to the pressure brake pads pressed against the brake discs. Regardless of the situation and the force the driver presses the brake pedal, the pressure in the brake system will be optimal.
The advantages of the system are that each wheel is analyzed and the optimal pressure is selected, thereby preventing wheel locking. Full braking occurs due to the pressure in the brake drive system, regulated by ABS.
This is the principle of ABS operation. On vehicles with rear and all-wheel drive there is only one touch sensor, which is located on the rear axle differential. Information about the possibility of blocking is taken from the nearest wheel, and the command about the required pressure is transmitted to all wheels.
The device that controls magnetic valves can operate in three modes:
- With the inlet valve open and the outlet valve closed, the device does not prevent pressure from increasing.
- The inlet valve receives the appropriate signal and remains closed, without changing the pressure.
- The exhaust valve receives a signal that the pressure is decreasing and opens, while the inlet valve closes and the pressure decreases as the check valve turns on.
Thanks to these modes, the pressure decreases and increases in a stepwise system. If problems arise, the ABS system is deactivated and the braking system operates without its participation. On dashboard the corresponding indicator indicates problems with ABS.
How to check the ABS sensor?
If the abs sensor is faulty, it does not transmit the necessary commands to the system and the automatic braking system ceases to perform its functions: when braking, the wheels lock. If the message on the dashboard lights up and does not go out, then you need to urgently contact service.
The induction type sensor is an induction coil that works in tandem with a toothed metal disk located on the wheel hub. Often the cause of the malfunction is a broken wire. It is this fault that we determine using a tester, a soldering iron and pins for repair.
The pins are connected to the connectors and the tester measures the resistance of the abs sensor, which must be within the limits specified in the operating manual. If the resistance tends to zero, then this indicates the presence of a short circuit. If it tends to infinity, then there is an open circuit.
Then the wheel is checked and the resistance is checked, it must be changed, in this case the sensor is working. If breaks are found during inspection, they must be repaired. Breaks should be connected only by soldering, not twisting, to avoid new breaks, oxidation, etc. Each device has its own marking, wire color and polarity. We must adhere to these data.
If the sensor is broken, you need to figure out how to remove the abs sensor and replace it. When choosing a device, you must first of all focus on quality.
To fully diagnose the sensors, you must not only check the contacts of the device itself with a tester, but you should also ring all its wiring. One of the reasons for incorrect operation is a violation of the integrity of the wiring. If the devices are working properly, then the resistance indicators are as follows:
- leg – front right abs sensor (7 - 25 Ohm);
- insulation resistance level – over 20 kOhm;
- leg – rear right abs sensor (6-24 Ohm).
Many cars have a self-diagnosis system. They display error codes on the information screen, which can be deciphered using the operating instructions.
What malfunctions can there be?
If you hear a cracking noise when you press the brake pedal, this is normal. This sound appears when modulators operate. If ABS is faulty, the indicator on the instrument panel lights up after turning on the ignition and does not go out, and continues to light when the engine is running.
There are four ABS fault states:
1). During the self-test, an error is detected and the ABS is deactivated. The reason may be an error in the controller unit or the presence of breaks in the wiring of the rear right abs sensor, or any other sensor. No angular velocity measurement signals are received.
2). After switching on, ABS successfully undergoes self-diagnosis and turns off. The reason may be broken wires, oxidation of contacts, poor connection at the contact points, broken power wire, short circuit of the sensor to ground.
3). After turning on, the ABS undergoes self-diagnosis and detects an error, but continues to work. This can happen if there is a break in one of the sensors.
4).
Information about the angular speed of the wheel comes from an additional device. The cause of this malfunction may be due to different tire pressures and tread patterns. If one tire is flat, or one wheel has a rougher tread than the others, the wheel will slow down. The same effect will occur if the car is equipped with tires with different degrees of wear.
5). ABS does not work. The reason may be a break in the wires, the wire near the sensor may have broken off, the wheel bearings may have worn out, there is play or there may be breaks in the wheel sensor rotor.
To correct problems, you need to check the play, tire pressure, and the condition of the wheel sensor rotor (comb). If the comb is chipped, it must be replaced. Check the condition of devices and wires that connect to them. If these measures do not help, then the problem is in the electronics. In this case, for accurate diagnosis you need to get the code.
Designed to record differences in wheel speed. Let's look at how to check the ABS sensor. Correct diagnostics will help you find the reason why the brake assistant malfunction indicator lights up on the dashboard.
Varieties of design
To calculate the angular speed of wheel rotation, 2 types of ABS sensor devices can be used:
- based on an inductive element. They are also called passive, since the sensitive element does not require external power, and the operating principle itself is based on the effect of electromagnetic induction. Despite the simplicity of design and reliability, such devices are becoming less and less common on modern cars. Main disadvantage designs - at low vehicle speeds it is impossible to adequately calculate the wheel speed;
- sensors based on the Hall effect. They are also called active, since the sensitive element needs power - a reference voltage. The signal produced by such speed sensors allows the ECU to more accurately calculate the wheel speed.
Design, principle of operation of inductive ABS sensors
Due to the principle of electromagnetic induction, the passage of the teeth of a comb mounted on the housing a near the iron core provokes voltage surges. Due to the rotation of the wheel, a sinusoidal voltage fluctuation is recorded at the terminals of the ABS sensor; frequency AC voltage directly proportional to the angular speed of rotation of the wheel.
The anti-lock brake system control unit registers and compares analog signals from all sensitive elements, which makes it possible to calculate the difference in the angular speeds of rotation of the wheels.
Multimeter test method
If you know, you can check the passive ABS sensor using even the cheapest universal meter. Correspondence possible malfunctions and methods for their diagnosis:
If the ABS sensor is removed from the car, then you can simulate the rotation of the master disk with any magnetic metal object.
Due to the aggressive installation environment, ABS sensors on motorcycles may have permanent magnet electromagnet, which must be taken into account when checking without dismantling (the ignition must be turned on).
How to make your search easier
In order not to carry out testing with a tester on each wheel separately, remove the connector of the ABS control unit. The video shows that once you understand the pinout, you can quickly find which circuit short circuit or a break.
Application of the Hall effect
Based on the effect of the occurrence of a transverse potential difference when placing a conductor with DC into a magnetic field. Change magnetic field When a gear passes near the sensing element, it provokes the occurrence of rectangular voltage surges. The pulse frequency allows the ABS control unit to calculate the actual wheel speed. 
Diagnostic method
Since the operating principle of the ABS sensor is based on the Hall effect, it self-check similar to the diagnosis of the speed sensor used in DPKV. A full check of the correctness of the signal can only be carried out with an oscilloscope, but for simple diagnostics a regular multimeter will do.
To check, you need to put the tester into measurement mode DC voltage. Connect the test leads to the signal contacts of the sensor, having previously supplied power through an additional resistance (a resistor with a value of 480 Ohms to 1.2 kOhms) and connecting the ground contact to an unpainted part of the car body. If the element is completely faulty, the marker disk rotating together with the CV joint will not provoke a change in the high and low level voltage.
Offline check
To operate, the sensitive element requires reference power, so without an external EMF source capable of delivering 9-12 V, it will not be possible to check the ABS sensor with a multimeter. It will also be necessary to include an additional resistor in the circuit (in the case of the Opel Vectra C brake system, as shown in the video, an element with a rating of 680 Ohms will be sufficient). The pinout of the connector can be found in the repair and operating manual for your car.
Since the sensitive element will be removed from the car, you can simulate the rotation of the marker disk by moving the magnet near the sensitive element.
In case of an open circuit, self-diagnosis ABS systems will definitely record the fact of a decrease in resistance in the sensor circuit and light up the ABS fault light on the dashboard. Some systems are capable of not only recording the fact of an error, but also calculating which wheel the breakdown occurred on. Therefore, if possible, the first step is to carry out computer diagnostics. On many cars, if more than 1 sensor breaks down, the system lights up not only the ABS fault light, but also the power indicator parking brake, after which the ABS turns off.
Before starting diagnostics with a multimeter, make sure that the air gap between the sensor and the marker disk is set correctly, and that the cavities of the marker disk themselves do not have dense dirt or corrosive deposits.
Be extremely careful when removing the sensor. They often stick, but impacts or other use of brute force can damage the plastic case. When installing, ensure that there is a correct air gap between the drive disc and the sensing element.
The crankshaft position sensor is an important element of the car, synchronizing the operation of the engine control unit. If it is damaged, synchronization will be disrupted, which will lead to breakdowns. However, the malfunction of this element is difficult to identify on your own, because this requires knowledge and appropriate tools.
Although often the breakdown of this element makes it impossible to start the engine, this is not always the case. If the crankshaft sensor is faulty, it can significantly reduce the efficiency of the vehicle, disrupt the timing of the fuel supply, cause spontaneous changes in speed, and much more.
Signs of sensor malfunction
A breakdown of the crankshaft sensor can be confused with problems with other vehicle mechanisms, including the fuel injection system or the unit that controls engine operation. Therefore, it is necessary to distinguish the characteristic features of this case, focusing on the “symptoms” of the car. Common symptoms of crankshaft sensor problems include:
- spontaneous change in speed dynamics;
- significant reduction in crankshaft characteristics;
- lack of stability in idle speed;
- problems starting the engine;
- detonation is possible in the engine under load.
These are just the main nuances that indicate a breakdown of the crankshaft sensor. They can be confused with problems with the generator or timing pulley. There are many signs of sensor failure, but most of them are individual and appear only in special cases.
However, nothing can be achieved by guessing; with such signs, it is worth taking the car to a service center or checking the condition of the crankshaft sensor yourself. Although it is quite difficult to access, using the instructions will allow you to quickly get to it and check its functionality. The test is quite simple and gives an accurate result that will indicate the health of the device.
Preparing the sensor before testing
There are several methods used to test this device. The simplest of them is to use a tester or multimeter, which will allow you to determine the condition of the crankshaft sensor based on its characteristics. However, it is also possible to use an oscilloscope, which is more often found in service workshops.
Before testing, you must remove the device from the vehicle. This is done in the following order:
- The ignition is turned off.
- The sensor connector is disconnected.
- The securing bolt is removed.
- The device itself is removed.
The removal procedure may vary depending on the vehicle and the mounting method.
Advice! To remove the bolt, use a 10mm wrench. The place is difficult to access, so you can’t get there with bulky tools.
During the removal process it is worth making visual inspection devices. If the breakdown is significant, then it can be noticed without any diagnostics. If the crankshaft sensor has severe external damage or cracks, then it should be replaced without additional checks.
Advice! When removing the device, it is better to make marks that determine its original position. This will simplify its further installation after testing.
After removing the sensor, you must thoroughly clean it of all contaminants. Before further testing, the contacts of the device must be clean, which will reliably determine its functionality.
Checking the sensor with a multimeter
For the first diagnostic method, you need to use a multimeter or tester. It is enough just to measure the resistance of the device winding by connecting it to the measuring equipment. If the winding has been damaged, this will affect the resistance readings.
Since a damaged coil changes the resistance of the crankshaft sensor, this test will determine its condition. You need to set the required range and connect the probes to the device outputs.
After checking, it is worth checking the received readings with the original ones. The average resistance of a working crankshaft sensor varies between 550-750 Ohms, but you can find exact value V technical instructions to the car. There probably is an accurate resistance indicator there.
Important! This test is unreliable and cannot guarantee an accurate test result. However, it is the simplest to perform, so if you have a multimeter, this will allow you to identify significant problems in the device.
There is also a second method for determining the performance of the crankshaft sensor. It is much more difficult, and to carry it out you need to take several devices, including:
- inductance meter;
- voltmeter;
- megohmmeter;
- network transformer.
The last two devices are replaced by a multimeter if it supports these functions.
The following measurements must be taken:
- Measuring winding resistance using an ohmmeter.
- Measuring winding inductance using an inductance meter.
- Determination of insulation resistance using a megohmmeter. Having applied a voltage of 500V, it is necessary to determine the resistance value.
Based on the data obtained, the condition of the crankshaft sensor is determined. Each indicator has a certain norm that you should focus on. The inductance of the winding varies between 200-400 mH; going beyond this range indicates a malfunction of the device. The winding resistance standard was previously mentioned and is 550-750 Ohms.
When measuring insulation resistance, the resulting value should not exceed 20 MΩ.
This data will make it possible to determine the functionality of the device or the presence of breakdowns, which will lead to its further replacement. However, there are more accurate diagnostic methods, among which the main one is checking with an oscilloscope. It is used in professional stations Maintenance and provides a complete diagnosis of this element.
Important! After diagnosing the device, it is worth checking the synchronization disk for magnetization. If it has received an extra charge, then it is worth demagnetizing it using a transformer.
If the check does not reveal a problem with the crankshaft sensor, then you need to install it back. In this case, you should be guided by the previously left marks. It is important to leave a small distance from the sensor to the disk, which should correspond to a value in the range of 0.5-1.5 mm.
Checking the sensor on an oscilloscope
To check the crankshaft sensor on an oscilloscope, there is no need to remove it from the car. Such diagnostics allow you to see signals during operation, rather than the performance of an individual device.
To check you need to take the following steps:
- Connect the black clamp of the oscilloscope to engine ground.
- Connect the probe probe parallel to the sensor output.
- The second connector of the probe is connected to output No. 5 of USB Autoscope II.
After this, all connections necessary to receive data from the vehicle will be completed. Next, you need to launch the “Inductive_Crankshaft” oscillogram mode. This will ensure the signal is broadcast in an understandable form.
To begin diagnostics, you need to start the car by starting the engine. If a breakdown puts it out of action, then you need to turn it with the starter.
If the crankshaft sensor does not produce signals, then this is a clear sign of its malfunction. If it is working, but the received data differs from the norm, then this indicates a malfunction of the device. Diagnostics using an oscilloscope will allow you to detect problems with the sensor and injection system, demonstrating all problems in the operation of the car in the form of waves and pulses.
Replacing the sensor
This element is one of the few that can completely disable a car. Therefore, sometimes it is necessary quick replacement so that the car can continue moving. To do this, you need a new device, the cost of which is relatively low, as well as a 10 or 12 wrench, which depends on the bolt on the mount.
The process occurs in the following order:
- The device is disconnected from power.
- All obstacles on the way are unscrewed (often these are protective elements).
- The fastening bolt securing the device is unscrewed.
- The defective device is removed and replaced with a new one.
- Reassembly is carried out in reverse order.
Advice! You should not use bulky wrenches, because the location of the bolt is difficult to reach. A large tool simply will not be able to turn there.
A malfunction of the crankshaft position sensor is an infrequent breakdown, so it is quite difficult to identify it yourself. Based on the main signs, it is worth checking the device using a conventional multimeter or other methods. If the failure is confirmed, it is worth replacing it. You can learn more about checking this sensor from the following video, which shows its diagnostics using a multimeter:
Every car owner knows that the operation of systems is controlled by special sensors. They are located in different places of the mechanisms. If such elements fail, the likelihood of malfunctions in the operation of system elements increases. In this case, repairs will be expensive. To eliminate the possibility of such a problem, periodically check the system sensors.
Control devices are responsible for the operation of many components and mechanisms. They need to be able to control them correctly. How to check temperature, pressure, air and other types of sensors will be discussed in detail in the article.
Sensor operation
Before you familiarize yourself with the technology of how to check the sensor idle move, oil pressure, temperature and other types of control devices, you need to consider the features of their operation.
The main devices of this type monitor the functioning of the motor and related systems. It is the engine that needs precise control of the operation of its elements and systems. Its failure entails the need for overhaul. To avoid large financial costs, it is recommended to check the functionality of the sensors.
Control devices are responsible for testing the heating level of the system and coolant. They provide measurement of the condition of various components during idling, in normal mode, etc. Every car owner should know how to check the temperature, air, oil pressure and other similar devices.
temperature sensor
There are a number of recommendations on how to check sensors on a VAZ, Chevrolet, Mercedes and other brands of cars. One of the most important indicators is a device that measures the heating of the coolant. This device transmits the collected data on the state of antifreeze to the engine control unit. He, in turn, adjusts his work based on the data received. In this case, the correct fuel supply level and ignition angle are adjusted.
On many cars (including VAZ, Kalina, Priora, Granda, etc.), the temperature control sensor switches the system to the electric ventilation type of cooling. Its readings are often displayed on the dashboard. This allows the driver to monitor the condition of the engine and its antifreeze. Modern vehicle models are equipped with temperature control sensors that have a negative heating coefficient. This means that as heating increases, the resistance of a given element decreases.
Operating principle of the temperature sensor
When considering how to check engine sensors, you need to study the basic principle of their operation. One of the most important things in the system is the antifreeze temperature control device. The control unit sends an electrical signal to this sensor. It has a voltage of 9 V. When this happens, the reader takes a resistance reading at the sensor contacts. The system sends this data back to the control unit. At the same time, she will be able to calculate, using a given logarithm, how the engine should operate under such circumstances.
If the temperature has increased, the resistance should decrease. In this case, the system, using its special mechanisms and electronic devices regulates the level of fuel consumed during engine operation. This allows you to reduce the heating temperature at the right time. Antifreeze in this case will be able to properly cool the system. When the temperature drops significantly, the presented mechanism will help adjust the engine operation in the opposite direction.
How to remove the sensor?
When considering how to check the coolant sensor, you need to know the correct element of the system. Drivers often confuse this element with the device that controls the fan. You don't need to look for it on the back of the fan. The temperature sensor is almost always installed in one of two possible locations. In the first case, an antifreeze heating control device can be installed near the thermostat. Moreover, it can be located directly in its body. In the second case, the sensor is installed in the cylinder head. It should be located in close proximity to one of the cooling system pipes.
To dismantle, you will need to drain the antifreeze from the radiator. Next they remove air filter, if the car is of the injection type. You can unscrew the sensor using wrench. In foreign cars, dismantling can be more difficult. Often the sensor is located at the rear of the cylinder head. In this case, during dismantling you will have to disconnect several hoses.
Checking the sensor operation
The method for checking the temperature sensor is described in detail by the manufacturer. vehicle. To carry out such work, you will need tools, a tester, a container of water, a stove, a thermometer with divisions up to 120 ºС, and a basin for antifreeze. First you need to turn off the radiator and drain the antifreeze from it. After this, the sensor is dismantled. The container with water should be placed on a gas or electric stove. The sensor must be lowered into the liquid. Its brass part should be completely immersed in water. The plastic should be on top.
You need to connect a tester to the device connectors. It is turned on in resistance measurement mode. Next, you need to heat the water and record the multimeter readings. You need to study the manufacturer's instructions, which indicate the operating parameters of the sensor. Most often, at a temperature of 100 ºС, the resistance is 150-200 Ohms. When the temperature drops to 20 ºС, this figure should increase to 3-4 kOhm. This indicates that the sensor is working properly. Otherwise it will need to be replaced.
Idle speed sensor
Drivers may be interested in how to check a car's idle speed sensor. This device is also responsible for ensuring stable engine operation. It only controls this process at idle. This sensor controls the amount of air that is supplied to the motor in this operating mode.
In this case, it is no longer the antifreeze liquid that is measured. The idle air system has certain constituent elements. It has a valve in the form of a conical needle. This element prevents air from entering the system. The needle is driven by a small motor that runs on electricity. The damper is set in motion when the motor is turned on. The needle can open or close the gap through which air enters the engine. Moreover, the diameter of this hole is also adjustable due to the special configuration of the damper.
Signs of malfunction
Before air, you should consider under what circumstances you need to suspect a malfunction of this particular element of the system. If the control device fails, the car will stall when stopping at traffic lights. In this case, the driver will have to hold the gas pedal while waiting for the green light.
Unstable engine speed also indicates a malfunction of the idle speed sensor. This can be heard even without the use of special equipment. It also takes a long time to warm up the engine. Even in warm weather, starting a car becomes problematic. Even after warming up, you have to drive on “choke” for a long time. The driver may also notice that when the transmission lever is moved to neutral, the engine begins to operate unstably. At the same time, it may even stall. In this case, you will need to check the idle speed sensor.
Checking the idle speed sensor
If the listed malfunctions appear, you need to consider how to check the idle speed sensor. It is located on the throttle valve. Her cable is attached next to it. Above the idle speed sensor there is a position control device throttle valve. You need to turn off the ignition and dismantle the presented device. The sensor can be attached using adhesive or bolts. In the first case, you will need to dismantle the entire throttle assembly. Bolted connection will only allow you to disconnect the sensor.
Next you need to connect the wires to the sensor on-board network. You need to place your finger on the conical needle. Next, the ignition is turned on. If after this you feel slight jolts of the needle, then the sensor is working. Otherwise, this structural element will be motionless. The sensor will need to be replaced.
Checking the oil pressure sensor
A malfunction of the oil pressure sensor can lead to engine malfunction. Therefore, it must be periodically checked for functionality. How to check the oil pressure sensor? There is a certain technology for this. It involves dismantling the control device. Next you need to connect the multimeter contacts to the sensor. He shows zero resistance. Next, use the pump to pump the oil. The chain must break. In this case, the device shows infinity. This indicates that the sensor is fully operational. Knowing how to check sensors, you can ensure normal operation of the motor and all systems for a long time.
Today, almost every car coming off the production line is equipped with an anti-lock brake system. This is not surprising, because ABS can provide real assistance during emergency braking in difficult situations. road conditions, significantly increasing the safety level of the machine. One of the most important elements This system includes sensors that record wheel speed.
The basic principle of operation of the ABS sensor, which is an induction coil working together with a toothed ring (comb), is to read electronic pulses and transmit information to the control unit. The unit itself, which controls the operation of the hydraulics, can regulate the fluid pressure in the brake system cylinders based on these readings.
The most common malfunctions that occur in ABS operation, an open circuit “sensor - control unit” and incorrect operation of the device itself, which incorrectly transmits the impulse, are considered. Problems with the anti-lock system can be felt when driving or recognized by the warning light on the dashboard. You can determine which element of the system is faulty by diagnosing it.
How to check the ABS sensor
What to do if the warning lamp on the instrument panel does not behave quite correctly? First of all, you need to check all ABS sensors. It should be noted that this procedure can be performed independently, without resorting to the services of highly paid specialists. To diagnose mechanisms, you will need a regular tester (multimeter), a vehicle operation/repair manual and a reliable assistant. You will also need to purchase wiring with special connectors (PIN).
Resistance check
So, what needs to be done to check the ABS sensor with a tester:
- hang the car on a lift or jack it up;
- remove the wheel if it prevents access to the part;
- unscrew the device fastening screw located on the back of the hub;
- remove the casing from the ABS control unit and disconnect the controller connectors;
- connect special repair PINs to the tester and the contact socket of one of the sensors;
- measure the resistance at the contacts of the device (the exact value can be found in the car repair instructions);
- “check” the integrity of the wiring, making sure there are no short circuits to ground.
Now you need to manually spin the wheel while simultaneously measuring the resistance - it is at this stage that you will need the help of a partner. The ohmmeter reading should change depending on the different wheel speeds.
Approximate resistance values of the working device are:
Voltage check
Another method for diagnosing devices, in which you need to switch the tester to the “voltmeter” mode and measure the voltage on each of the sensors:
- the car is lifted with a jack, hanging the wheels;
- PIN connectors are connected to the contact socket of the device;
- the wheel is turned at a frequency of one revolution per second, taking readings from the device.
Attention! The tester arrow should be located in the range of 0.25-1.2 V, and it must be taken into account that an increase in the speed of rotation of the wheel necessarily “raises” the voltage value.
To make the process of diagnosing the device more clear, it is recommended to watch the video “How to check the ABS sensor with a tester (multimeter)”
Other diagnostic methods
In addition to the above methods for checking the ABS sensor, this device can be diagnosed with a special device - an oscilloscope, which measures the amplitude and resistance level. The disadvantage of the method is that this equipment very expensive and very difficult to use. An oscilloscope is a rather rare device and checking an ABS sensor with it requires certain skills, so a separate review is worth devoting to a description of this method.
Majority anti-lock systems modern cars equipped with a self-diagnosis function. After its activation on the information monitor on-board computer Error codes will be displayed in alphanumeric format. The decoding of these symbols can be easily found using the machine's instruction manual or using the Internet.
Attention! Only correct diagnostics of the sensor allows you to repair or replace the device without much effort and wasting time.
DIY ABS sensor repair
A few words need to be said about the repair of ABS system elements, which can be easily performed at home. Naturally, if the problem point is the sensor itself, then it will have to be replaced, but in the case of wiring, you can fix the defect yourself. To restore its integrity, it is necessary to use only the “soldering” method and carefully wrap the joints with insulating tape.
Attention! Each ABS sensor has a polarity - this must be taken into account when connecting wiring to it. The car repair instructions indicate the color coding of the wires; the connecting connector of the device must have the same designation.
Replacing the ABS sensor
Before replacing the ABS sensor, it is necessary to eliminate the main reasons causing its incorrect operation. It is known that each car model has a number of specific problem areas that need special attention. For example, Ford cars produced before 2000 almost universally suffer from interruptions in the operation of electrical equipment, which occur due to frequent short circuits. The “pain point” of these machines is the poor quality of wire insulation.
The peculiarity of replacing the device is that the front ABS sensor can be removed both from the engine compartment and from below the car body, this will depend on the design features of the car. Get close to the equipment installed on rear wheels cars, only from below. Step-by-step instruction, presented to the reader’s attention by experienced specialists, describes only general principles work, but this method is quite applicable to the majority of both domestic and imported cars.
Necessary equipment
To replace the ABS sensor you will need:
- reliable hydraulic jack;
- key - “balloon”;
- hammer;
- open-end wrenches 28 and 32;
- socket wrenches (heads) for 10 and 12;
- flat screwdriver;
- voltage tester;
- insulating tape;
- liquid WD - 40 in a can.
Work order
Let's look at the step-by-step implementation of all the work using the example of replacing the rear right ABS sensor:
View from the interior: 1 - connector; 2 - clamp; 3 - overlay; 4 - sensor wire
View of the rear part of the hub: 1 - bracket; 2 - mounting bolt.
View of the arch: 1 and 2 - wire fixation points; 3 - plug.
- Installation of the new device is carried out as follows: the part is inserted into place (with little force) and secured with a bolt.
- Next, tighten the bolts that secure the bracket to the arch and shock absorber.
- Now you can insert the plug and push the wire into the interior.
- It is necessary to install the sensor wire under the cover so that its connector fits into the socket. The anti-vibration pad is glued and carefully smoothed.
- You can install the wheel by first tightening it and then tightening it all the way wheel nuts.
- The next step Replacing the ABS sensor will involve checking its functionality. Using a tester connected to the connectors, the voltage is measured. This process is described in detail in the section on checking voltage when diagnosing a device.
All that remains is to connect the connector, place the terminal on the battery and lower the wheel. The door seal, side trim and sill trim are put in place and reassembled removed seats and trunk curtain (if equipped).
Attention! Before putting the trim elements in place, you need to turn on the ignition, start the car engine and make sure that the ABS warning light goes out 3-5 seconds after the start.
When replacing devices located on the steering knuckles of the front wheels, the situation is somewhat simpler, thanks to more convenient access to these parts:
- jack up the car and remove the right wheel;
- unscrew the bolts securing the front ABS sensor to steering knuckle and remove it from seat;
- release the wire fastening and disconnect the connector plug;
- We perform the installation in the reverse order, making sure that no dirt gets into the sensor mounting area.
Final functionality check
After replacing the device and installing all dismantled parts, a final check of the functionality of the ABS system is performed. On the road, you need to choose a safe area and brake sharply at a speed of 20-40 km/h, pressing the pedal all the way down. If vibration is felt under your foot and the characteristic sound of the pads being activated is heard, the system is operating normally.
Summarizing
It has been established that a properly performed check of the ABS sensor with a tester is the primary task when repairing the system. You can use any convenient testing method, but you should always remember that diagnostics alone will not solve the problem - you will have to replace the device or “repair” the electrical wires. In order for the ABS to perform its task during braking, it is very important to monitor the condition of the sensors, checking, repairing and replacing them in a timely manner. Let's hope that our review and this video can help you carry out this “operation” yourself.
