ABS sometimes works and sometimes doesn't
Another ABS fault is that the ABS warning light is always on and the brakes at 20km/h will lock. There are three reasons for this failure:
1. ECU failure.
2. Mechanical failure.
3. The wheel speed sensor is faulty.
MK type ABS belongs to the four-wheel independent control. Its working principle is to transmit the signal to the ECU through the wheel speed sensor, and the ECU instructs the hydraulic regulator to control the braking system.
For this kind of hidden fault, ABS sometimes works, sometimes it doesn't work, first check whether the ECU works normally, then check whether the mechanical part is normal, and then further check whether the wheel speed sensor is normal.
Check from the appearance first. If there is any debris, remove the sensor for cleaning. When re-inserting and installing, there should be a gap of about 0.05 between the iron core of the wheel speed sensor and the wheel bearing. Then turn the left rear wheel and use the digital multimeter to shift the millivolt range. Measure the output voltage of the sensor and confirm that it is within the standard range.
The ABS system is to make full use of the adhesion coefficient between the tire and the ground, so that each brake can generate as much braking force as possible without locking, improve the braking ability of the car, and improve the maneuverability and stability of the vehicle. If you encounter a fault, you should first understand the environment where the vehicle often travels and whether other faults encountered are related to the ABS fault, and then make corresponding maintenance.
