ABS sensor.
Abs sensor is used in the motor vehicle ABS (Anti-lock Braking System). In the ABS system, the speed is monitored by an inductive sensor. The abs sensor outputs a set of quasi-sinusoidal AC electrical signals through the action of the gear ring that rotates synchronously with the wheel, and its frequency and amplitude are related to the wheel speed. The output signal is transmitted to the ABS electronic control unit (ECU) to realize real-time monitoring of wheel speed.
1, linear wheel speed sensor
Linear wheel speed sensor is mainly composed of permanent magnet, pole axis, induction coil and tooth ring. When the gear ring rotates, the tip of the gear and the backlash alternate opposite polar axis. During the rotation of the gear ring, the magnetic flux inside the induction coil changes alternately to generate the induction electromotive force, and this signal is input to the electronic control unit of ABS through the cable at the end of the induction coil. When the speed of the gear ring changes, the frequency of the induced electromotive force also changes.
2, ring wheel speed sensor
Annular wheel speed sensor is mainly composed of permanent magnet, induction coil and tooth ring. The permanent magnet is composed of several pairs of magnetic poles. During the rotation of the gear ring, the magnetic flux inside the induction coil changes alternately to generate the induction electromotive force. This signal is input to the electronic control unit of ABS through the cable at the end of the induction coil. When the speed of the gear ring changes, the frequency of the induced electromotive force also changes.
3, Hall type wheel speed sensor
When the gear is located in the position shown in (a), the magnetic field lines passing through the Hall element are dispersed and the magnetic field is relatively weak; When the gear is located in the position shown in (b), the magnetic field lines passing through the Hall element are concentrated and the magnetic field is relatively strong. When the gear rotates, the density of the magnetic line of force passing through the Hall element changes, which causes the Hall voltage to change, and the Hall element will output a millivolt (mV) level of quasi-sine wave voltage. This signal also needs to be converted by the electronic circuit into a standard pulse voltage.
Does a broken rear abs sensor affect 4-drive
May be
Damage to the rear ABS sensor can affect the all-wheel drive system, especially if the all-wheel drive system is equipped with differential locking. This is because the rear wheel sensor plays an important role in the anti-lock braking system (ABS), once damaged, the ABS system may not accurately perceive the speed and status of the wheel, which affects its braking effect, and may even lead to the wheel lock during braking, increasing the risk of driving. In addition, if the four-wheel drive system is equipped with a differential lock function, damage to the rear wheel sensor may cause the differential lock to not work properly, which will affect the performance of the four-wheel drive system. Therefore, although the damage of the rear wheel sensor may not directly affect the basic function of the four-wheel drive system, in order to ensure driving safety, it is recommended to repair or replace the damaged sensor in time.
ABS rear wheel sensor may fail due to wear.
ABS sensor failures include ABS light on the dashboard, ABS not working properly, and traction control light on. These failures can be caused by sensors wearing out, disconnecting, or being struck by debris. Especially the rear wheel ABS sensor, if the iron scraps generated by the grinding of the brake disc and brake pad are adsorbed by the magnet, may lead to the distance between the sensor and the magnet coil becoming smaller, or even wear, eventually lead to the sensor damage.
In order to determine whether the ABS sensor is damaged, can be detected by the following methods:
Read the fault diagnosis instrument's fault code: If there is a fault code in the ABS computer, and the fault light on the instrument is on, this may indicate that the sensor is damaged.
Field brake test: in a good road surface, wide and unmanned place, speed up to more than 60, and then put the brake to the end. If the wheel is locked and there is no braking frustration, this may indicate ABS failure, is usually caused by damage to the ABS sensor.
Use a multimeter to measure the voltage/resistance of the ABS sensor: Turn the wheel at 1r/s, the output voltage of the front wheel should be between 790 and 1140mv, the rear wheel should be higher than 650mv. In addition, the resistance value of ABS sensors is generally between 1000 and 1300Ω. If these ranges are not met, may indicate a problem with the ABS sensor 34.
In summary, if there is a problem with the ABS rear wheel sensor, should first check whether there is physical damage, such as fracture or obvious wear. If there is no obvious physical damage performance degradation due to wear or other causes can be further diagnosed by the above methods.
If you want to know more, keep reading the other articles on this site!
Please call us if you need such products.
Zhuo Meng Shanghai Auto Co., Ltd. is committed to selling MG&MAUXS auto parts welcome to buy.
