Inspection Procedure

1. Using the intelligent tester, check for any momentary interruption in the wire harness and connector corresponding to a DTC (See CHECK FOR INTERMITTENT PROBLEMS ).

ABS / VSC / TRAC: 

OK: There are no momentary interruptions. 

HINT:

Perform the above inspection before removing the sensor and connector.

NG: GO TO step   10 

OK: Go to next step 

1. Connect the intelligent tester to the DLC3.
2. Turn the ignition switch ON position.
3. Select the DATA LIST mode on the intelligent tester.

   ABS/VSC/TRAC: 

   MEASUREMENT ITEM NORMAL CONDITION CHART
   
   

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

4. 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.

OK: GO TO step   8 

NG: Go to next step 

1. Check the sensor installation.

   OK: There is no clearance between the sensor and rear axle carrier. 

   The installation bolt is tightened properly. 

   Torque: 8.0 N*m (82 kgf*cm, 71 in.*lbf) 

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

NG: CHECK AND REPLACE FRONT SPEED SENSOR 

Fig 1: Clearance Between Sensor And Rear Axle Carrier With Torque Specification

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

OK: Go to next step 

1. Make sure that there is no looseness at the connector's locking part and connecting part of the connector.
2. Disconnect the speed sensor connector.
3. Measure the resistance according to the value(s) in the table below.

   Resistance: 

   LH 

   TESTER CONNECTION SPECIFIED CONDITION CHART
   
   

   Tester Connection	Specified Condition
   2 (FL+) - 1 (FL-)	1.4 to 1.8 kΩ

   RH 

   TESTER CONNECTION SPECIFIED CONDITION CHART
   
   

   Tester Connection	Specified Condition
   2 (FR+) - 1 (FR-)	1.4 to 1.8 kΩ

   Fig 2: Inspecting Front Speed Sensor

   Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
4. Measure the resistance according to the value(s) in the table below.

Resistance: 

LH 

RH 

NG: REPLACE FRONT SPEED SENSOR 

OK: Go to next step 

1. Disconnect the skid control ECU connectors and the front speed sensor connectors.
2. Measure the resistance according to the value(s) in the table below.

   Resistance: 

   LH 

   TESTER CONNECTION SPECIFIED CONDITION CHART
   
   

   Tester Connection	Specified Condition
   S2-1 (FL-) - S41-22 (FL-)	Below 1 Ω
   S2-2 (FL+) - S41-28 (FL+)	Below 1 Ω

   RH 

   TESTER CONNECTION SPECIFIED CONDITION CHART
   
   

   Tester Connection	Specified Condition
   S3-1 (FR-) - S38-22 (FR-)	Below 1 Ω
   S3-2 (FR+) - S38-32 (FR+)	Below 1 Ω

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

Resistance: 

LH 

Fig 3: Identifying Skid Control ECU Connectors And Front Speed Sensor Connectors

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

RH 

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Connect the skid control ECU connectors.
2. Connect the oscilloscope to terminals S38-32 (FR+) and S38-22 (FR-) or S41-28 (FL+) and S41-22 (FL-) of the skid control ECU.
3. Drive the vehicle at approximately 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.

NG: CLEAN OR REPLACE FRONT SPEED SENSOR AND SENSOR ROTOR 

Fig 4: Identifying Skid Control ECU Connector And Waveform Graph

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

OK: Go to next step 

1. Connect the intelligent tester to the DLC3.
2. Turn the ignition switch on.
3. Select the DATA LIST mode on the intelligent tester.

   ABS/VSC/TRAC: 

   MEASUREMENT ITEM NORMAL CONDITION CHART
   
   

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

4. 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.

NG: REPLACE SKID CONTROL ECU 

OK: END 

1. Perform sensor signal check in TEST MODE PROCEDURE (See TEST MODE PROCEDURE ).

   OK: All test mode DTCs are erased. 

NG: GO TO step   3 

OK: Go to next step 

1. Connect the oscilloscope to terminals S38-32 (FR+) and S38-22 (FR-) or S41-28 (FL+) and S41-22 (FL-) of the skid control ECU.
2. Drive the vehicle at approximately 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.

NG: CLEAN OR REPLACE FRONT SPEED SENSOR AND SENSOR ROTOR 

Fig 5: Identifying Skid Control ECU Connector And Waveform Graph

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

OK: END 

1. Clear the DTC (See DTC CHECK / CLEAR ).
2. Turn the ignition switch on.
3. Drive the vehicle at the speed of 32 km/h (20 mph) or more, for 60 seconds or more, and drive in reverse at a speed of 3 km/h (2 mph) or more, for approximately 5 seconds.
4. Check that the same DTC is recorded (See DTC CHECK / CLEAR ).

   HINT:

   Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

Result 

B: GO TO step   2 

A: END