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 (REAR 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 RR	Wheel speed sensor (RR) reading / min.: 0 km/h (0 MPH), max.: 326 km/h (202 MPH)	Actual wheel speed
WHEEL SPD RL	Wheel speed sensor (RL) 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 REAR SPEED SENSOR

Disconnect the skid control sensor connector.

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

Standard:

TESTER CONNECTION SPECIFIED CONDITION (1 OF 2)

Tester Connection	Specified Condition
1 - 2	0.9 to 2.1 kΩ

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

Standard:

TESTER CONNECTION SPECIFIED CONDITION (2 OF 2)

Tester Connection	Specified Condition
1 - Body ground	10 kΩ or higher
2 - Body ground	10 kΩ or higher

Fig 1: Measuring Rear Speed Sensor Resistance

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Skid control sensor sub-wire harness:

Remove the seat cushion and seatback.
Make sure that there is no looseness at the locking part and connecting part of the connector.

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

Fig 2: Measuring Skid Control Sensor Sub-Wire Harness Resistance

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard:

LH:

TESTER CONNECTION SPECIFIED CONDITION LH

Tester Connection	Specified Condition
A32 (A-1) - A32 (A-2)	10 kΩ or higher

RH:

TESTER CONNECTION SPECIFIED CONDITION RH

Tester Connection	Specified Condition
A33 (A-1) - A33 (A-2)	10 kΩ or higher

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

Standard:

LH:

TESTER CONNECTION SPECIFIED CONDITION LH

Tester Connection	Specified Condition
A32 (A-1) - A32 (B-2)	Below 1 Ω
A32 (A-2) - A32 (B-1)	Below 1 Ω

RH:

TESTER CONNECTION SPECIFIED CONDITION RH

Tester Connection	Specified Condition
A33 (A-1) - A33 (B-2)	Below 1 Ω
A33 (A-2) - A33 (B-1)	Below 1 Ω

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

Standard:

LH:

TESTER CONNECTION SPECIFIED CONDITION LH

Tester Connection	Specified Condition
A32 (A-1) - Body ground	10 kΩ or higher
A32 (A-2) - Body ground	10 kΩ or higher

RH:

TESTER CONNECTION SPECIFIED CONDITION RH

Tester Connection	Specified Condition
A33 (A-1) - Body ground	10 kΩ or higher
A33 (A-2) - Body ground	10 kΩ or higher

NG: REPLACE REAR SPEED SENSOR OR SUB-WIRE HARNESS
NOTE: Check the speed sensor signal after replacement (see TEST MODE PROCEDURE ).

OK: Go to Next Step.

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

Disconnect the skid control ECU connector S1 and the skid control sensor connector S25 or S26.

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

Standard:

LH:

TESTER CONNECTION SPECIFIED CONDITION LH

Tester Connection	Specified Condition
S1-6 (RL-) - A32-2 (RL-)	Below 1 Ω
S1-20 (RL+) - A32-1 (RL+)	Below 1 Ω

RH:

TESTER CONNECTION SPECIFIED CONDITION RH

Tester Connection	Specified Condition
S1-19 (RR-) - A33-2 (RR-)	Below 1 Ω
S1-5 (RR+) - A33-1 (RR+)	Below 1 Ω

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

Fig 3: Disconnecting Skid Control ECU Connector S1 And Skid Control Sensor Connector S25 Or S26

Standard:

LH:

TESTER CONNECTION SPECIFIED CONDITION LH

Tester Connection	Specified Condition
S1-6 (RL-) - Body ground	10 kΩ or higher
S1-20 (RL+) - Body ground	10 kΩ or higher

RH:

TESTER CONNECTION SPECIFIED CONDITION RH

Tester Connection	Specified Condition
S1-19 (RR-) - Body ground	10 kΩ or higher
S1-5 (RR+) - 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 RR+ - RR- or RL+ - RL- 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 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.
  
  Fig 4: Normal Signal Waveform
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: Go to step 5
OK: REPLACE BRAKE ACTUATOR ASSY (SEE REPLACEMENT )
INSPECT REAR SPEED SENSOR INSTALLATION
1. Check the sensor installation.
  OK: There is no clearance between the sensor and rear axle carrier.
  
  Fig 5: Inspecting Rear Speed Sensor Installation
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: REPLACE REAR 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 AND SENSOR TIP
1. Remove the skid control sensor (see REPLACEMENT ).
2. Check the sensor tip.
  OK: No scratches or foreign matter on the sensor tip.
3. Check the sensor rotor serrations.
  OK: No scratches, missing teeth or foreign objects.
  
  Fig 6: Checking Sensor Rotor Serrations
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: CLEAN OR REPLACE SPEED SENSOR AND SENSOR ROTOR SERRATIONS
  NOTE: Check the speed sensor signal after replacement (see TEST MODE PROCEDURE ).
OK: REPLACE BRAKE ACTUATOR ASSY (SEE REPLACEMENT )