Inspection Procedure

1. Check speed sensor. 

   Front preparation  :

   1. Remove the front fender liner.
   2. Disconnect the speed sensor connector.

   Check  : Measure the resistance between terminals 1 and 2 of speed sensor connector.

   Fig 1: Testing Front Speed Sensor

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK  : Resistance: 0.6-2.5 kΩ (1.6 +/- 0.2 kΩ at 20°C).

   Check  : Measure the resistance between terminals 1 and 2 of speed sensor connector and body ground.

   OK  : Resistance: 1 MΩ or higher.

   Rear preparation

   1. Remove the seat cushion and seatback.
   2. Disconnect the speed sensor connector.

   Check  : Measure the resistance between terminals 1 and 2 of speed sensor connector.

   Fig 2: Testing Rear Speed Sensor

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK  : Resistance: 1.2-2.3 kΩ (1.6 +/- 0.1 kΩ at 20°C).

   Check  : Measure the resistance between terminals 1 and 2 of speed sensor connector and body ground.

   OK  : Resistance: 1 MΩ or higher.

   NG  : Replace speed sensor.

   NOTE: Check the speed sensor signal last. See STEP 2 - SPEED SENSOR SIGNAL CHECK (TEST MODE) .

   If OK  , go to step  2.

2. Check for open and short circuit in harness and connector between each speed sensor and ABS & BA & TRAC & VSC ECU  . See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE .

   NG  : Repair or replace harness or connector.

   If OK  , go to step  3.

3. Check speed sensor installation. 
   Fig 3: Identifying Possible Cause Of Speed Sensor Malfunction

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK  : The installation bolt shall be tightened properly and no clearance is allowed between the sensor and front steering knuckle or rear axle carrier.

   NG  : Replace speed sensor.

   NOTE: Check the speed sensor signal last. See STEP 2 - SPEED SENSOR SIGNAL CHECK (TEST MODE) .

   If OK  , go to step  4.

4. Check speed sensor and sensor rotor serrations. 

   Reference  : Inspection using oscilloscope.

   Preparation  :

   1. Disconnect the connector from the ABS & BA & TRAC & VSC ECU.
   2. Connect the oscilloscope to the terminals FR+, FL+, RR+ or RL+ and GND of the ECU harness side connector.

   Check:  Drive the vehicle at about 30 km/h (19 mph), and check the signal waveform.

   Fig 4: Identifying Normal Signal Waveform

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK:  Check and replace ABS & BA & TRAC & VSC ECU.

   If NG  , go to step  5.

5. Check sensor rotor and sensor tip. 

Front preparation  : Remove the front drive shaft. See REMOVAL .

Check  : The sensor rotor serrations.

Fig 5: Inspecting Front Rotor Serrations

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK  : No scratches, missing teeth or foreign objects.

Preparation  : Remove the front speed sensor. See step 3) of REMOVAL .

Check  : Check the sensor tip.

OK  : No scratches or foreign objects on the sensor tip. 

Rear preparation:  Remove the axle hub. See REMOVAL .

Check:  the sensor rotor serrations.

Fig 6: Inspecting Rear Rotor Serrations

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: No scratches, missing teeth or foreign objects. 

Preparation:  Remove the rear speed sensor. See step 1 of REMOVAL .

Check:  the sensor tip.

OK:  No scratches or foreign objects on the sensor tip.

NG:  Replace sensor rotor or speed sensor.

OK:  Check and replace ABS & BA & TRAC & VSC ECU.