How to Test a Vehicle Wheel Speed Sensor?
2 Answers
Methods for testing a vehicle wheel speed sensor: Check the gap between the wheel speed sensor and the gear ring. The standard value for the front wheels is 1.10 to 1.97mm, and for the rear wheels, it is 0.42 to 0.80mm. An excessive gap will directly affect data accuracy. Check the output voltage section by rotating the wheel at a speed of 1 revolution per second and measuring the output voltage with a multimeter. The normal range for the front wheels is 190 to 1140mV, while the rear wheels require a voltage greater than 650mV. The wheel speed sensor is used to measure the rotational speed of a vehicle's wheels. Commonly used wheel speed sensors include: magnetic wheel speed sensors and Hall-effect wheel speed sensors.
Last time I was tinkering with the wheel speed sensor on my old car in the garage, I first unplugged the connector to check for rust or looseness—those things are easily damaged by mud and water. Then I borrowed an OBD scanner to read the fault codes directly. If it showed a C-prefixed ABS code, that was pretty much it. Next, I took off the wheel and measured the resistance with a multimeter; it should normally be around 1000 ohms. If the reading was unusually low or infinite, it meant the sensor was done for. Finally, I manually rotated the bearing to listen for any abnormal clicking sounds from the sensor and cleaned the metal shavings off the magnetic ring. After finishing, remember to take it for a test drive—if the ABS light goes off, then it’s fixed. Doing it yourself can save hundreds in labor costs, but if you’re inexperienced, it’s best not to mess around with it.
