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 referecnce 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 circuit continuously.
If the sensor signal current is continuously out of the specified range for 140msec, then the HECU determines that the circuit is open/short, and sets this code.
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 (6.2mph).
DTC Detecting Condition
Item | Detecting Condition | Possible cause |
DTC Strategy | Current Monitoring
| Open or short of Wheel speed sensor circuit Faulty Wheel speed sensor
|
Enable Conditions | When the sensor signal current is continuously out of the specified range of 4 mA ± 10% ~ 22 mA ± 10% for 140msec.
|
Fail Safe | Only one wheel failure : Inhibit the ABS/ESP control, allow the EBD control. The ABS/ESP warning lamps are activated, the EBD warning lamp is not activated. More than two wheels failure : The ABS/EBD/ESP functions are inhibited. The ABS/EBD/ESP warning lamps are activated.
|
Specification
Sensor Type | Output Voltage | Airgap |
HIGH | LOW |
Active Type | 1.4V | 0.7V | 0.4~1.5mm |
Diagnostic Circuit Diagram
Signal Waveform & Data
Fig 1) Normal waveform of wheel speed sensor (Active type)
- High : Approx. 1.4V, Low : Approx. 0.7V