Tacoma Extra Cab 2WD L4-2438cc 2.4L DOHC MFI (1997)
Wheel Speed Sensor: Description and Operation
Speed Sensor Circuit Description
CIRCUIT DESCRIPTION
The speed sensor detects wheel speed and sends the appropriate signals to the Electronic Control Unit (ECU). These signals are used to control of
the Anti-Lock Brake System (ABS) system. The front and rear rotors each have 48 serrations.
When the Rotors rotate, the magnetic field emitted by the permanent magnet in the speed sensor generates an AC voltage. Since the frequency of
this AC voltage changes in direct proportion to the speed of the rotor, the frequency is used by the ECU to detect the speed of each wheel.
FAIL SAFE FUNCTION
If trouble occurs in the speed sensor circuit, the ECU cuts off current to the ABS control (solenoid) relay and prohibits ABS control.
