Toyota RM787U, Руководство по обслуживанию и ремонту

Страница: 161 / 1976

BR3583
BR3582
F00010
Rotor
Speed Sensor
Magnet
To ECU
+V
-V
High Speed
Low Speed
Coil
N S
- DIAGNOSTICS ANTI-LOCK BRAKE SYSTEM
DI-233
387
Author: Date:
2001 SIENNA (RM787U)
DTC 31 - 34 Speed Sensor Circuit
CIRCUIT DESCRIPTION
The speed sensor detects wheel speed and sends the ap-
propriate 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 perma-
nent magnet in the speed sensor generates an AC voltage.
Since the frequency of this AC voltage changes in direct propor-
tion to the speed of the rotor, the frequency is used by the ECU
to detect the speed of each wheel.
DTC No. DTC Detecting Condition Trouble Area
31, 32, 33, 34
Detection of any of conditions from 1. through 4.:
1. With vehicle speed at 10 km/h or more, sensor signal
circuit of faulty wheel is open or short for 15 sec. or long-
er.
2. Momentary interruption of sensor signal of faulty wheel
has occurred 7 times or more.
3. With vehicle speed at 20 km/h or more, sensor signal of
faulty wheel generated noise for 5 sec. or longer.
4. Sensor signal circuit is open for 0.3 sec. or longer.
Right front, left front, right rear, left rear speed sensor
Each speed sensor circuit
Sensor installation
Sensor rotor
HINT:
DTC No. 31 is for the right front speed sensor.
DTC No. 32 is for the left front speed sensor.
DTC No. 33 is for the right rear speed sensor.
DTC No. 34 is for the left rear speed sensor.
DI8AV-01