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.
Wheel speed sensor is active hall-sensor type.






DTC Description

The ABS ECU monitors the wheel speed sensor signal continuously.
The failure detection is started if the original wheel speed changes erratically with a signal step of |Vx (n) - Vx (n-1) | > 25 km/h (15.5 mph). An offset of about 5 km/h (3.1 mph) will be added to the threshold in case rough road is detected or the number of interrupts from the wheel speed sensor reach a value of 40 per loop. An extrapolated wheel speed signal will be calculated, the start value is set to the vehicle reference speed.
Further on, the extrapolated wheel speed signal follows the calculated speed signal with a limited gradient of max 0.57 kph (0.4 mph) per loop.
Warning lamp is turned OFF unless additional faults are detected when the IG KEY is turned ON again, and wheel speed is more than 10 km/h (6.2 mph).

DTC Detecting Condition









Specification





Schematic Diagram