Inspection Procedure

NOTE: When replacing the brake actuator assy, perform zero point calibration (see CALIBRATION ).

HINT:

Start the inspection from step 1 when using the hand-held tester and start from step 2 when not using the hand-held tester.

READ VALUE OF HAND-HELD TESTER (FRONT SPEED SENSOR)

Connect the hand-held tester to the DLC3.
Start the engine.

Select DATA LIST mode on the hand-held tester.

DATA LIST

Item	Measurement Item / Range (Display)	Normal Condition
WHEEL SPD FR	Wheel speed sensor (FR) reading / min.: 0 km/h (0 MPH), max.: 326 km/h (202 MPH)	Actual wheel speed
WHEEL SPD FL	Wheel speed sensor (FL) reading / min.: 0 km/h (0 MPH), max.: 326 km/h (202 MPH)	Actual wheel speed

Check that there is no difference between the speed value output from the speed sensor displayed on the hand-held tester and the speed value displayed on the speedometer when driving the vehicle.
OK: There is almost no difference in the displayed speed value.

HINT:

There is tolerance of +/- 10 % in the speedometer indication.

OK: Go to step 4

NG: Go to Next Step.

INSPECT FRONT SPEED SENSOR

Make sure that there is no looseness at the locking part and connecting part of the connector A6 or A7.
Disconnect the speed sensor connector.

Measure the resistance according to the value (s) in the table below.

Fig 1: Measuring Front Speed Sensor Resistance

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard:

LH:

TESTER CONNECTION SPECIFIED CONDITION LH

Tester Connection	Specified Condition
A6-1 (FL+) - A6-2 (FL-)	0.92 to 1.22 kΩ at 20°C

RH:

TESTER CONNECTION SPECIFIED CONDITION RH

Tester Connection	Specified Condition
A7-1 (FR+) - A7-2 (FR-)	0.92 to 1.22 kΩ at 20°C

Measure the resistance according to the value (s) in the table below.

Standard:

LH:

TESTER CONNECTION SPECIFIED CONDITION LH

Tester Connection	Specified Condition
A6-1 (FL+) - Body ground	10 kΩ or higher
A6-2 (FL-) - Body ground	10 kΩ or higher

RH:

TESTER CONNECTION SPECIFIED CONDITION RH

Tester Connection	Specified Condition
A7-1 (FR+) - Body ground	10 kΩ or higher
A7-2 (FR-) - Body ground	10 kΩ or higher

NG: REPLACE FRONT SPEED SENSOR (SEE REPLACEMENT )
NOTE: Check the speed sensor signal after replacement (see TEST MODE PROCEDURE ).

OK: Go to Next Step.

CHECK HARNESS AND CONNECTOR (FRONT SPEED SENSOR - SKID CONTROL ECU)

Disconnect the skid control ECU connector S1 and the front speed sensor connector A6 or A7.

Measure the resistance between terminals of the skid control ECU and front speed sensor.

Standard:

LH:

TESTER CONNECTION SPECIFIED CONDITION LH

Tester Connection	Specified Condition
S1-4 (FL-) - A6-2 (FL-)	Below 1 Ω
S1-18 (FL+) - A6-1 (FL+)	Below 1 Ω

RH:

TESTER CONNECTION SPECIFIED CONDITION RH

Tester Connection	Specified Condition
S1-17 (FR-) - A7-2 (FR-)	Below 1 Ω
S1-3 (FR+) - A7-1 (FR+)	Below 1 Ω

Measure the resistance between terminals of the skid control ECU harness side connector and body ground.

Fig 2: Disconnecting Skid Control ECU Connector S1 And Front Speed Sensor Connector A6 Or A7

Standard:

LH:

TESTER CONNECTION SPECIFIED CONDITION LH

Tester Connection	Specified Condition
S1-4 (FL-) - Body ground	10 kΩ or higher
S1-18 (FL+) - Body ground	10 kΩ or higher

RH:

TESTER CONNECTION SPECIFIED CONDITION RH

Tester Connection	Specified Condition
S1-17 (FR-) - Body ground	10 kΩ or higher
S1-3 (FR+) - Body ground	10 kΩ or higher

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to Next Step.

INSPECT SPEED SENSOR AND SENSOR ROTOR SERRATIONS
INSPECTION USING OSCILLOSCOPE
1. Connect the oscilloscope to terminals FR+ - FR- or FL+ - FL- of the skid control ECU.
2. Drive the vehicle at about 19 mph (30 km/h) and check the signal waveform.
  
  Fig 3: Normal Signal Waveform
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  OK: A waveform as shown in the figure should be output.
  
  HINT:
  - 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.
1. OK: REPLACE BRAKE ACTUATOR ASSY (SEE REPLACEMENT )
NG: Go to Next Step.
INSPECT FRONT SPEED SENSOR INSTALLATION
1. Check the speed sensor installation.
  
  Fig 4: Inspecting Front Speed Sensor Installation
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  OK:
  
  There is no clearance between the sensor and front steering knuckle.
  
  The installation bolt is tightened properly.
  
  Torque: 8.0 N.m (82 kgf.cm, 71 in. lbf)
1. NG: REPLACE FRONT SPEED SENSOR
  NOTE: Check the speed sensor signal after replacement (see TEST MODE PROCEDURE ).
OK: Go to Next Step.
INSPECT SPEED SENSOR TIP
1. Remove the front speed sensor (see REPLACEMENT ).
2. Check the sensor tip.
  OK: No scratches or foreign matter on the sensor tip.
1. NG: CLEAN OR REPLACE SPEED SENSOR (SEE REPLACEMENT )
  NOTE: Check the speed sensor signal after replacement (see TEST MODE PROCEDURE ).
OK: Go to Next Step.
INSPECT SPEED SENSOR ROTOR
1. Remove the front drive shaft.
2. Check the sensor rotor serrations.
  
  Fig 5: Checking Sensor Rotor Serrations
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  OK: No scratches, missing teeth or foreign matter. HINT:
  
  If there is foreign matter in the rotor, remove it and check the output waveform after reassembly.
1. NG: REPLACE OUTBOARD JOINT SHAFT ASSY (SEE REPLACEMENT )
  NOTE: Check the speed sensor signal after replacement (see TEST MODE PROCEDURE ).
OK: REPLACE BRAKE ACTUATOR ASSY (SEE REPLACEMENT )