Inspection Procedure

1. Check the size and condition of all 4 tires.

   HINT:

   This DTC is output when tire deformation or a difference in tire size is detected.

   OK: 

   The diameter of all 4 tires and air pressure are the same. 

1. NG: REPLACE TIRES SO THAT ALL 4 TIRES ARE SAME IN SIZE 
2. OK: Go to next step. 

INSPECTION USING OSCILLOSCOPE 

1. Disconnect the skid control ECU connector.
2. Connect the oscilloscope to each speed sensor terminal of the skid control ECU connector.
   SPEED SENSOR AND SENSOR ROTOR SERRATIONS (1 OF 2)
   
   

   Connector	Circuit
   A40-5 (FL+) - A40-6 (FL-)	Front left speed sensor
   A40-10 (FR+) - A40-9 (FR-)	Front right speed sensor
   A40-7 (RL+) - A40-17 (RL-)	Rear left speed sensor
   A40-19 (RR+) - A40-8 (RR-)	Rear right speed sensor

3. Check that a waveform is output when the tires are rotated (by the sensor circuit).

   OK: 

   A waveform as shown in  Fig 1  and  Fig 2  should be output. 

   Fig 1: Inspecting Speed Sensor And Sensor Rotor Serrations Using Oscilloscope (1 Of 2)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   Fig 2: Inspecting Speed Sensor And Sensor Rotor Serrations Using Oscilloscope (2 Of 2)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   HINT:

   • Each sensor circuit outputs the same waveform without noise.
   • As vehicle speed (wheel rotation speed) increases, the width 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 rotor scratches, looseness or foreign matter attached to the speed sensor.
4. Make sure that the waveform does not change while jiggling a connector or a wire harness.

   OK: 

   The waveform does not change. 

HINT:

If the waveform changes while jiggling a connector or a wire harness, there may be a malfunction in the connector on the wire harness.

Result: 

1. B: REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL ECU TO SPEED SENSOR) 
2. C: CHECK OR REPLACE SPEED SENSOR AND SENSOR ROTOR (SEE  DTC C0200/31 RIGHT FRONT SPEED SENSOR, DTC C0205/32 LEFT FRONT SPEED SENSOR, DTC C1330/35 RIGHT FRONT SPEED SENSOR CIRCUIT, DTC C1331/36 LEFT FRONT SPEED SENSOR CIRCUIT, DTC C1271/71 LOW OUTPUT VOLTAGE OF RIGHT FRONT SPEED SENSOR (TEST MODE DTC), DTC C1272/72 LOW OUTPUT VOLTAGE OF LEFT FRONT SPEED SENSOR (TEST MODE DTC), DTC C1275/75 ABNORMAL CHANGE IN OUTPUT VOLTAGE OF RIGHT FRONT SPEED SENSOR (TEST MODE DTC), DTC C1276/76 ABNORMAL CHANGE IN OUTPUT VOLTAGE OF LEFT FRONT SPEED SENSOR (TEST MODE DTC)   OR  DTC C0210/33 RIGHT REAR SPEED SENSOR, DTC C0215/34 LEFT REAR SPEED SENSOR, DTC C1332/38 RIGHT REAR SPEED SENSOR CIRCUIT, DTC C1333/39 LEFT REAR SPEED SENSOR CIRCUIT, DTC C1273/73 LOW OUTPUT VOLTAGE OF RIGHT REAR SPEED SENSOR (TEST MODE DTC), DTC C1274/74 LOW OUTPUT VOLTAGE OF LEFT REAR SPEED SENSOR (TEST MODE DTC), DTC C1277/77 ABNORMAL CHANGE IN OUTPUT VOLTAGE OF RIGHT REAR SPEED SENSOR (TEST MODE DTC), >DTC C1278/78 ABNORMAL CHANGE IN OUTPUT VOLTAGE OF LEFT REAR SPEED SENSOR (TEST MODE DTC)   ) 
3. A: Go to next step. 

1. Clear the DTC.
2. Start the engine.
3. Drive the vehicle at the speed of 20 mph (32 km/h) or more for 60 seconds or more.
4. Check that the same DTC is recorded.

   Result: 

   RECONFIRM DTC
   
   

   DTC is not output	A
   DTC is output	B

1. B: REPLACE BRAKE ACTUATOR ASSY (SEE  REPLACEMENT  ) 
2. A: END