DESCRIPTION
The speed sensor detects wheel speed and sends the appropriate signals to the ECU. These signals are used to control the ABS control system. The front and rear rotors have 48 serrations each.
When the rotors rotate, the magnetic field emitted by the permanent magnet in the speed sensor generates 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.
HINT:
WIRING DIAGRAM
INSPECTION PROCEDURE
1 READ VALUE ON INTELLIGENT TESTER (FRONT SPEED SENSOR)
(a) Connect the intelligent tester to the DLC3.
(b) Start the engine.
(c) Select the DATA LIST mode on the intelligent tester.
ABS / VSC:
(d) Check that there is no difference between the speed value output from the speed sensor displayed on the intelligent tester and the speed value displayed on the speedometer when driving the vehicle.
OK: There is almost no difference from the displayed speed value.
HINT: There is tolerance of +- 10 % in the speedometer indication.
2 CHECK SPEED SENSOR AND SENSOR ROTOR SERRATIONS
(a) INSPECTION USING OSCILLOSCOPE
(1) Connect the oscilloscope to terminal FR+ and FRor FL+ and FL- of the skid control ECU.
(2) Drive the vehicle at about 19 mph (30 km/h), and check the signal waveform.
OK: A waveform as shown in a figure should be output.
HINT:
NOTICE: When replacing the brake actuator assembly, perform zero point calibration (See page BC-70).
REPLACE BRAKE ACTUATOR ASSEMBLY
3 INSPECT FRONT SPEED SENSOR
(a) Make sure that there is no looseness at the connectors' locking part and connecting part of connector.
(b) Disconnect the speed sensor connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:
LH
RH
(d) Measure the resistance according to the value(s) in the table below
Standard resistance:
LH
RH
NOTICE: Check the speed sensor signal after replacement (See page BC-72).
4 CHECK HARNESS AND CONNECTOR (FRONT SPEED SENSOR - SKID CONTROL ECU)
(a) Disconnect the skid control ECU connector and the front speed sensor connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
LH
RH
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:
LH
RH
5 CHECK SPEED SENSOR AND SENSOR ROTOR SERRATIONS
(a) INSPECTION USING OSCILLOSCOPE
(1) Connect the oscilloscope to terminal FR+ and FRor FL+ and FL- of the skid control ECU.
(2) Drive the vehicle at about 19 mph (30 km/h), and check the signal waveform.
OK: A waveform as shown in a figure should be output.
HINT:
NOTICE: When replacing the brake actuator assembly, perform zero point calibration (See page BC-70).
REPLACE BRAKE ACTUATOR ASSEMBLY
6 CHECK FRONT SPEED SENSOR INSTALLATION
(a) Check the speed sensor installation.
OK: The installation bolt is tightened properly. There is no clearance between the sensor and the front steering knuckle.
Torque: 8.0 N*m (82 kgf*cm, 71 in.*lbf)
NOTICE: Check the speed sensor signal after the replacement (See page BC-72).
7 CHECK FRONT SPEED SENSOR TIP
(a) Remove the front speed sensor (See page BC-187).
(b) Check the sensor tip.
OK: No scratches or foreign matter on the sensor tip.
NOTICE: Check the speed sensor signal after the replacement (See page BC-72).
8 CHECK SPEED SENSOR ROTOR
(a) Remove the front drive shaft (See page DS-5).
(b) Check the sensor rotor serrations.
OK: No scratches, missing teeth or foreign matter on the rotors.
HINT: If there is foreign matter in the rotor, remove it and check the output waveform after reassembly.
REPLACE BRAKE ACTUATOR ASSEMBLY
DTC check / clear
HINT:
Illustrations may differ from the actual vehicle depending
on the device settings and options. Therefore, some
detailed areas may not be shown exactly the same as on
the actual vehicle.
If the system cannot enter the diagnostic mode, inspect all AVC-LAN
communication ...
Disposal
HINT:
When scrapping a vehicle equipped with the SRS or
disposing of the front passenger airbag assembly, be sure to
deploy the airbag first in accordance with the procedure
described below. If any abnormality occurs with airbag
deployment, contact the SERVICE DEPT. of the TOYOTA
MOTOR SALES, ...
Disassembly
1. REMOVE STEERING INTERMEDIATE SHAFT ASSEMBLY
(a) Align the matchmarks on the steering intermediate
shaft assembly and main shaft.
(b) Remove the bolt and steering intermediate shaft
assembly.
2. REMOVE KEY CYLINDER LIGHT ASSEMBLY (w/o
Engine Immobiliser System)
3. REMOVE TRANSPONDER K ...