ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1464/31, C1271/71, C1272/72, C1465/32

DESCRIPTION

The speed sensor detects wheel speed and sends the appropriate signals to the ECU. These signals are used to control the ABS system. This speed sensor contains a sensor IC, which consists of 2 MREs (Magnetic Resistance Element). The speed sensor rotor, which consists of 48 sets of N and S poles that are arranged in a circle, is integrated with the inner race of the hub bearing.

To detect the rotation direction, the output waves are used to determine the relationship of the pulses that are generated by 2 MREs. Upon receiving this signal, the sensor IC outputs a forward or backward wave to the ECU.

DTCs C1271/71 and C1272/72 can be deleted when the speed sensor sends a vehicle speed signal or the Test Mode ends. DTCs C1271/71 and C1272/72 are output only in the Test Mode.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)

   
   

   1. Using the intelligent tester, check for any momentary interruption in the harness and connector corresponding to a DTC Click here.

      ABS/VSC/TRC:

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      FR Speed Sensor Open	Front speed sensor RH open detection / Error or Normal	Error: Momentary interruption Normal: Normal	-
      FL Speed Sensor Open	Front speed sensor LH open detection / Error or Normal	Error: Momentary interruption Normal: Normal	-

      OK
      There are no momentary interruptions.

      Tech Tips

      Perform the above inspection before removing the sensor and connector.

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR (SPEED SENSOR CIRCUIT)

   OK

2. READ VALUE USING INTELLIGENT TESTER (FRONT WHEEL SPEED / FRONT WHEEL DIRECTION)

   
   

   1. Connect the intelligent tester to the DLC3.

   2. Turn the power switch ON (READY).

   3. Select the DATA LIST mode on the intelligent tester.

   4. Check that the speed value output from the speed sensor displayed on the intelligent tester and the speed value displayed on the speedometer are almost the same when driving the vehicle.

      ABS/VSC/TRC:

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      FR Wheel Speed	Front wheel speed sensor RH reading / min.: 0 km/h (0 mph), max.: 326 km/h (202 mph)	Actual wheel speed	Similar speed as indicated on speedometer
      FL Wheel Speed	Front wheel speed sensor LH reading / min.: 0 km/h (0 mph), max.: 326 km/h (202 mph)	Actual wheel speed	Similar speed as indicated on speedometer

      OK
      The speed value output from the speed sensor displayed on the intelligent tester is the same as the actual vehicle speed.

   5. Check that the sensor signal conforms to the wheel direction.

      ABS/VSC/TRC:

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      FR Wheel Direction	Front wheel direction RH / Forward or Back	Forward: Forward Back: Back	-
      FL Wheel Direction	Front wheel direction LH / Forward or Back	Forward: Forward Back: Back	-

      OK
      The wheel direction is displayed.

   
   

   NG

   INSPECT FRONT SPEED SENSOR INSTALLATION Click here

   OK

3. PERFORM TEST MODE (SIGNAL CHECK)

   
   

   1. Clear the DTC Click here.

   2. Perform sensor signal check in "TEST MODE PROCEDURE" Click here.

      OK
      All Test Mode DTCs are erased.

   
   

   NG

   INSPECT FRONT SPEED SENSOR INSTALLATION Click here

   OK

4. RECONFIRM DTC

   
   

   1. Clear the DTC Click here.

   2. Turn the power switch ON (READY).

   3. Drive the vehicle at a speed of 32 km/h (20 mph) or more for 60 seconds or more.

   4. Check if the same DTCs are recorded Click here.

      Result

      Result	Proceed to
      DTCs (C1464/31 and C1465/32) are not output	A
      DTCs (C1464/31 and C1465/32) are output	B

      Tech Tips

      If troubleshooting has been carried out according to the "PROBLEM SYMPTOMS TABLE", refer back to the table and proceed to the next step Click here.

   
   

   B

   REPLACE FRONT SPEED SENSOR Click here

   A

   USE SIMULATION METHOD TO CHECK Click here

5. INSPECT FRONT SPEED SENSOR INSTALLATION

   
   

   1. 

      Check the sensor installation Click here.

      OK
      There is no clearance between the sensor and the front steering knuckle, and the installation bolt is tightened properly.

      Note

      Check the speed sensor signal after reinstallation Click here.

   
   

   NG

   SECURELY REINSTALL FRONT SPEED SENSOR Click here

   OK

6. INSPECT FRONT SPEED SENSOR TIP

   
   

   1. Remove the front speed sensor.

   2. Check the sensor tip.

      OK
      No scratches or foreign matter on the sensor tip.

      Note

      Check the speed sensor signal after cleaning/replacement Click here.

   
   

   NG

   CLEAN OR REPLACE FRONT SPEED SENSOR Click here

   OK

7. CHECK SKID CONTROL SENSOR WIRE

   
   

   1. 

      Disconnect the skid control sensor wire RH connectors (vehicle side: A55, sensor side: A).

   2. Disconnect the skid control sensor wire LH connectors (vehicle side: A91, sensor side: A).

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

      Standard resistance
      for RH
      Tester Connection Condition Specified Condition A-2 (FR+) - A55-2 (FR+) Always Below 1 Ω A-2 (FR+) - A55-1 (FR-) Always 10 kΩ or higher A-2 (FR+) - Body ground Always 10 kΩ or higher A-1 (FR-) - A55-1 (FR-) Always Below 1 Ω A-1 (FR-) - A55-2 (FR+) Always 10 kΩ or higher A-1 (FR-) - Body ground Always 10 kΩ or higher
      for LH
      Tester Connection Condition Specified Condition A-2 (FL+) - A91-1 (FL+) Always Below 1 Ω A-2 (FL+) - A91-2 (FL-) Always 10 kΩ or higher A-2 (FL+) - Body ground Always 10 kΩ or higher A-1 (FL-) - A91-2 (FL-) Always Below 1 Ω A-1 (FL-) - A91-1 (FL+) Always 10 kΩ or higher A-1 (FL-) - Body ground Always 10 kΩ or higher

      Note

      Check the speed sensor signal after replacement Click here.

   
   

   NG

   REPLACE SKID CONTROL SENSOR WIRE Click here

   OK

8. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - SKID CONTROL SENSOR WIRE)

   
   

   1. Disconnect the A19 and A21 ECU connectors.

   2. Disconnect the A55 sensor wire connector.

   3. Disconnect the A91 sensor wire connector.

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

      Standard resistance
      for RH
      Tester Connection Condition Specified Condition A19-16 (FR+) - A55-2(FR+) Always Below 1 Ω A19-15 (FR-) - A55-1 (FR-) Always Below 1 Ω A19-16 (FR+) - Body ground Always 10 kΩ or higher A19-15 (FR-) - Body ground Always 10 kΩ or higher
      for LH
      Tester Connection Condition Specified Condition A21-16 (FL+) - A91-1 (FL+) Always Below 1 Ω A21-15 (FL-) - A91-2 (FL-) Always Below 1 Ω A21-16 (FL+) - Body ground Always 10 kΩ or higher A21-15 (FL-) - Body ground Always 10 kΩ or higher

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

9. CHECK SKID CONTROL ECU (SENSOR INPUT VOLTAGE)

   
   

   1. 

      Reconnect the A19 and A21 ECU connectors.

   2. Disconnect the A55 sensor wire connector.

   3. Disconnect the A91 sensor wire connector.

   4. Turn the power switch ON (IG).

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition A55-2 (FR+) - Body ground Power switch ON (IG) 6.7 to 14 V A91-1 (FL+) - Body ground Power switch ON (IG) 6.7 to 14 V

      Result

      Result		Proceed to
      OK		A
      NG	for LHD	B
      	for RHD	C

   
   

   B

   REPLACE SKID CONTROL ECU Click here

   C

   REPLACE SKID CONTROL ECU Click here

   A

10. RECONFIRM DTC

    
    

    1. Clear the DTC Click here.

    2. Turn the power switch ON (READY).

    3. Drive the vehicle at a speed of 32 km/h (20 mph) or more for 60 seconds or more.

    4. Check if the same DTCs are recorded Click here.

       Tech Tips

       Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

       Result

       Result	Proceed to
       DTCs (C1464/31 and C1465/32) are output	A
       DTCs (C1464/31 and C1465/32) are not output	B

       Tech Tips

       If troubleshooting has been carried out according to the "PROBLEM SYMPTOMS TABLE", refer back to the table and proceed to the next step Click here.

    
    

    B

    USE SIMULATION METHOD TO CHECK Click here

    A

11. REPLACE FRONT SPEED SENSOR

    
    

    1. Replace the front speed sensor Click here.

       Note

       Check the speed sensor signal after replacement Click here.

    
    

    NEXT

12. RECONFIRM DTC

    
    

    1. Clear the DTC Click here.

    2. Turn the power switch ON (READY).

    3. Drive the vehicle at a speed of 32 km/h (20 mph) or more for 60 seconds or more.

    4. Check if the same DTCs are recorded Click here.

       Tech Tips

       Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

       Result

       Result	Proceed to
       DTCs (C1464/31 and C1465/32) are output	A
       DTCs (C1464/31 and C1465/32) are not output	B

       Tech Tips

       If troubleshooting has been carried out according to the "PROBLEM SYMPTOMS TABLE", refer back to the table and proceed to the next step Click here.

    
    

    B

    END

    A

13. INSPECT SPEED SENSOR ROTOR

    
    

    1. Remove the front axle hub and bearing (speed sensor rotor) Click here.

    2. Check the sensor rotor.

       OK
       No scratches, oil, or foreign matter on the rotor.

       Tech Tips

       If the sensor rotor is damaged, replace the front axle hub and bearing assembly.

       Note

       
       

       • Do not use any kind of cleaner when cleaning the speed sensor rotor.

       • Check the speed sensor signal after cleaning/replacement Click here.

       Result

       Result		Proceed to
       NG		A
       OK	for LHD	B
       	for RHD	C

    
    

    B

    REPLACE SKID CONTROL ECU Click here

    C

    REPLACE SKID CONTROL ECU Click here

    A

    CLEAN OR REPLACE FRONT AXLE HUB AND BEARING ASSEMBLY (SPEED SENSOR ROTOR) Click here