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Fig. 47: Normal Signal Waveform
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
4.INSPECT FRONT SPEED SENSOR
Page 66 of 4500
Fig. 48: Inspecting Front Speed Sensor
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
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:
TESTER CONNECTION SPECIFIED CONDITION LH:
TESTER CONNECTION SPECIFIED CONDITION RH:
d. Measure the resistance accordin
g to the value (s) in the table below.
Tester ConnectionSpecified Condition
A8-2 (FL+) - A8-1 (FL-)0.6 to 2.5 kohms
Tester ConnectionSpecified Condition
A7-2 (FR+) - A7-1 (FR-)0.6 to 2.5 kohms
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Standard:
TESTER CONNECTION SPECIFIED CONDITION LH:
TESTER CONNECTION SPECIFIED CONDITION RH:
FRONT SPEED SENSOR SUB-WIRE HARNESS
a. Remove the front fender liner.
b. Make sure that the speed sensor connector and the wire harness side connector are securely
connected.
c. Disconnect the speed sensor connector inside the vehicle.
d. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION LH:
TESTER CONNECTION SPECIFIED CONDITION RH:
e. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION LH:
TESTER CONNECTION SPECIFIED CONDITION RH:
Tester ConnectionSpecified Condition
A8-2 (FL+) - Body ground1 Mohms or higher
A8-1 (FL-) - Body ground1 Mohms or higher
Tester ConnectionSpecified Condition
A7-2 (FR+) - Body ground1 Mohms or higher
A7-1 (FR-) - Body ground1 Mohms or higher
Tester ConnectionSpecified Condition
(Connector A-1) - (Connector B-1)Below 1 ohms
(Connector A-2) - (Connector B-2)Below 1 ohms
Tester ConnectionSpecified Condition
(Connector A-1) - (Connector B-1)Below 1 ohms
(Connector A-2) - (Connector B-2)Below 1 ohms
Tester ConnectionSpecified Condition
(Connector A-1) - (Connector A-2)1 Mohms or higher
Tester ConnectionSpecified Condition
(Connector A-1) - (Connector A-2)1 Mohms or higher
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f. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION LH:
TESTER CONNECTION SPECIFIED CONDITION RH:
NG: REPLACE FRONT SPEED SENSOR (SEE REPLACEMENT
)
Tester ConnectionSpecified Condition
(Connector A-1) - Body ground1 Mohms or higher
(Connector A-2) - Body ground1 Mohms or higher
Tester ConnectionSpecified Condition
(Connector A-1) - Body ground1 Mohms or higher
(Connector A-2) - Body ground1 Mohms or higher
Page 69 of 4500
Page 70 of 4500
Fig. 49: Identifying Speed Sensor Connector And Wire Harness Side Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: Go to next step
5.CHECK HARNESS AND CONNECTOR (FRONT SPEED SENSOR - SKID CONTROL ECU)
Fig. 50: Identifying Skid Control ECU Connector And Front Speed Sensor Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
a. Disconnect the skid control ECU connector and the front speed sensor connector.
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b. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION LH:
TESTER CONNECTION SPECIFIED CONDITION RH:
c. Measure the resistance according to the value (s) in the table below.
Standard:
TESTER CONNECTION SPECIFIED CONDITION LH:
TESTER CONNECTION SPECIFIED CONDITION RH:
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
6.INSPECT SPEED SENSOR AND SENSOR ROTOR SERRATIONS
INSPECTION USING OSCILLOSCOPE
a. Connect the oscilloscope to terminal FR+ - FR- or FL+ - FL- of the skid control ECU.
b. Drive the vehicle at approximately 19 mph (30 km/h), and check the signal waveform.
OK: Go to next step
A waveform as shown in a figure should be output.
HINT:
Tester ConnectionSpecified Condition
S42-18 (FL+) - A8-2 (FL+)Below 1 ohms
S42-4 (FL-) - A8-1 (FL-)Below 1 ohms
Tester ConnectionSpecified Condition
S42-3 (FR+) - A7-2 (FR+)Below 1 ohms
S42-17 (FR-) - A7-1 (FR-)Below 1 ohms
Tester ConnectionSpecified Condition
S42-18 (FL+) - Body ground1 Mohms or higher
S42-4 (FL-) - Body ground1 Mohms or higher
Tester ConnectionSpecified Condition
S42-3 (FR+) - Body ground1 Mohms or higher
S42-17 (FR-) - Body ground1 Mohms or higher
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As the vehicle speed (Wheel revolution speed) increases, a cycle of the waveform narrows and the
fluctuation in the output voltage becomes greater.
When noise is identified in the waveform on the oscilloscope, error signals are generated due to the
speed sensor rotor's scratches, looseness or foreign matter attached to it.
NG: Go to step 7
Fig. 51: Normal Signal Waveform
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK: REPLACE ABS & TRACTION ACTUATOR ASSY (SEE REPLACEMENT
)
7.INSPECT FRONT SPEED SENSOR INSTALLATION
a. Check the speed sensor installation.
OK: Go to next step