ABS means antilock brake system,which automatically control the force of the brake, in case that the wheel be locked.
However, the ABS light will light up. What is the reason?Here are three situations of that.
ABS lights Always On
1.When the vehicle speed exceeds 10km/h, no speed signal is transmitted to the ABS control unit.
2.When the vehicle speed is greater than 40km/h, the speed signal exceeds the tolerance value.
3.The sensor has an identifiable open circuit or short-circuit fault to the positive pole and ground.
If you encounter the above situation, you should check the following items
1.Is wire connection between wheel speed sensor and ABS control unit still works.
2.The gap between speed sensor and the gear ring
3.Whether the gap of wheel bearing is too large.
4.Whether the sensor is damaged.
Tips：When cleaning the vehicle, high-pressure water is often used to flush the engine compartment. The water may splash into the connection point of the ABS control unit, which will cause instantaneous disconnection after corrosion.
ABS lights On While Driving
Usually it indicates that system is faulty.There are two situations in this way.
1.If ABS light is the only one turns on during driving, it indicates that there is a fault in the ABS system, but the car is still under the control of braking system,it needs be repaired by professionals as soon as possibl
2.If the ABS light and the braking light are on at the same time during driving, it indicates that there are faults in both the ABS and the braking system, and the braking system may be invalid in this situation.
If you encounter the last situation, you must stop driving immediately and check the brake fluid level. If the fluid level is lower than the "min" mark, you must not continue driving, and ask a professional for maintenance. If the liquid level is normal, it indicates that the ABS system may be malfunctioning, that is, the ABS system adjustment function fails, and only the ordinary brake system works. It is easy to cause the rear wheels to lock up quickly when braking, leading to sideslip. At this time, you should drive cautiously and perform repairs as soon as possible.
The general steps for fault diagnosis and troubleshooting are as follows:
1.Check whether there is any brake fluid leakage, wire breakage, loose plug, low brake fluid level, etc.
2.To read the fault code, you can either use the decoder to read it directly, or you can read the fault code through the warning light, and then find the fault situation represented by the fault code according to the maintenance manual.
3.According to the fault situation of the interpretation, use the necessary tools and instruments to conduct an in-depth inspection of the fault location to confirm the fault location and the cause of the fault.
5.Clear the fault code;
6.Check whether the warning light is still on. If the warning light is still on, it may be that there is still a fault in the system, or it may be that the fault has been eliminated and the fault code has not been cleared; after the warning light is no longer powered, Carry out a road test to confirm whether the system is back to work.
The ABS fault light turns on repeatedly and then goes off for no reason
It is most likely that water has entered the sensor interface. Don't rush to replace it. You can go to the repair shop to check it first. They have an instrument that can detect the sensors. After finding faulty sensor , don't change it first, and then clean the inside by yourself. For dirt, seal the interface and then tighten it. The sensor is very strong and generally won’t break.