General Information
Component Location
General Description
The wheel speed sensor is the essential component the ABS ECU uses to calculate vehicle speed and to determine whether wheel lock occurs. For example, rear wheel speed signal is used as a reference value, for vehicle speed, in front wheel drive vehicles, and if a difference between front and rear wheel speed occurs, then ABS control is performed. The wheel speed sensor generates sine wave signals, based on magnetic field made by a permanent magnet in the speed sensor, when the tone wheel rotates. The frequency and AC voltage changes in proportion to the wheel speed, and the HECU determines the speed by calculating the frequency of the signal.
DTC Description
The ABS ECU monitors the wheel speed sensor signal continuously. The monitoring method for this sensor is to check the (-) side signal of the sensor circuit when a reference voltage is applied to (+) side of the sensor circuit. If the (-) side voltage is out of normal range (2.15 - 3.5 V) for more than 140 ms when the vehicle is operating below 7 Km/h, then the HECU determines that the circuit is open/short, and sets this code. Warning lamp is turned OFF if the detected fault is not more than when the IG KEY is turned to ON again, and wheel speeds are more than 10 Km/h.
DTC Detecting Condition
Specification
Schematic Diagram
Signal Waveform