Circuit Description

WARNING: This page is about a different car, the 2002 Toyota Sienna. However, it is still accessible from the selected car via links, so may be relevant.

The speed sensor detects wheel speed and sends the appropriate signals to the ECU. These signals are used to control of the 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.

Fig 1: Diagramming Speed Sensor Signal Generation

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: Identifying Speed Sensor Circuit DTC's & Trouble Areas

NOTE:

DTCs No. C0200/31 and C1235/35 are for the right front speed sensor.
DTCs No. C0205/32 and C1236/36 are for the left front speed sensor.
DTCs No. C0210/33 and C1238/38 are for the right rear speed sensor.
DTCs No. C0215/34 and C1239/39 are for the left rear speed sensor.