SENSOR, Wheel Speed, Front: Operation: Operation
WARNING: This page is about a different car, the 2011 RAM Pickup and 2011 RAM Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The sensors convert wheel speed into an electrical signal. This signal and amperage is changed by magnetic induction when the toothed tone wheel passes the wheel speed sensor. This signal is sent to the ABM which measures the voltage and amperage of the digital signal for each wheel to determine wheel speed.
The signal strength is affected by the distance between the sensor and the tone ring. If the "Air Gap" between the sensor and the tone ring/wheel is too large, the signal can drop out at low speed, (below 40 mph) and can cause an ABS activation. No adjustment is available for the air gap.