Inspection Procedure

HINT:

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

READ VALUE OF HAND-HELD TESTER (SKID CONTROL SENSOR)
1. Select the item "WHEEL SPEED RL (RR)" in the DATA LIST and read its value displayed on the hand-held tester.
2. 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 from the displayed speed value.
HINT:

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

OK: CHECK AND REPLACE BRAKE ACTUATOR ASSY (SEE REPLACEMENT )

NG: Go to Next Step.
INSPECT SKID CONTROL SENSOR
1. Make sure that there is no looseness at the locking part and connecting part of the connector.
2. Disconnect the skid control sensor connector.
3. Measure the resistance between terminals 1 and 2 of the skid control sensor connector.
  Standard: 1.3 to 1.6 kΩ at 20°C
4. Measure the resistance between terminals 1 and 2 of the skid control sensor connector and body ground.
  Standard: 10 kΩ or higher
  
  Fig 1: Measuring Skid Control Sensor Terminals Resistance
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Skid control Sensor Sub-Wire Harness:
1. Remove the seat cushion and seatback.
2. Make sure that there is no looseness at the locking part and connecting part of the connector.
3. Measure the resistance between terminal 1 of connector 1 and terminal 2 of connector 2.
4. Measure the resistance between terminal 2 of connector 1 and terminal 1 of connector 2.
  Standard: 1 Ω or lower
  
  Fig 2: Inspecting Skid Control Sensor
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
5. Measure the resistance between terminals 1 and 2 of speed sensor connector 1 and body ground.
  Standard: 10 kΩ or higher
1. NG: REPLACE SKID CONTROL 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 (SKID CONTROL SENSOR - BRAKE ACTUATOR ASSY) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE )
1. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to Next Step.
INSPECT SENSOR AND SENSOR ROTOR SERRATIONS
(REFERENCE) 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 12 mph (20 km/h) and check the signal waveform.
  OK: A waveform as shown in the figure should be output.
HINT:
- As the vehicle speed (rpm of the wheels) increases, a cycle of the waveform narrows and the fluctuation in the output voltage becomes greater.
  
  Fig 3: Normal Signal Waveform
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- 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 on it.
1. OK: CHECK AND REPLACE BRAKE ACTUATOR ASSY
NG: Go to Next Step.
INSPECT SKID CONTROL SENSOR INSTALLATION
1. Check the skid control sensor installation.
  OK: There is no clearance between the sensor and rear axle carrier.
  
  Fig 4: Inspecting Skid Control Sensor Installation
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: REPLACE SKID CONTROL SENSOR
  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.
1. OK: CHECK AND REPLACE BRAKE ACTUATOR ASSY (SEE REPLACEMENT )
NG: CLEAN OR REPLACE SPEED SENSOR AND SENSOR ROTOR

NOTE: Check the speed sensor signal after replacement (see TEST MODE PROCEDURE ).