ANTI-LOCK BRAKE SYSTEM(for Type B), Diagnostic DTC:C1273,C1274,C1277,C1278,C1415 and C1416

DTC Code DTC Name
C1273 Low Output Signal of Rear Speed Sensor RH (Test Mode DTC)
C1274 Low Output Signal of Rear Speed Sensor LH (Test Mode DTC)
C1277 Abnormal Change in Output Signal of Rear Speed Sensor RH (Test Mode DTC)
C1278 Abnormal Change in Output Signal of Rear Speed Sensor LH (Test Mode DTC)
C1415 Rear Speed Sensor RH Output Malfunction
C1416 Rear Speed Sensor LH Output Malfunction

DESCRIPTION

Each speed sensor detects the wheel speed and sends signals to the skid control ECU (brake actuator assembly). These signals are used by the ABS.

The speed sensor rotors have rows of alternating N and S magnetic poles. Hall IC type speed sensors use the frequency of output pulses to detect the vehicle speed. Because the sensor outputs digital pulses, it can detect the vehicle speed even when the vehicle is nearly stationary.

DTCs C1273 and C1274 are cleared when the speed sensor sends a vehicle speed signal or when Test Mode ends. DTCs C1273 and C1274 are output only in Test Mode.

C151818E22
Tip:

Check the connection status between the sensor connector and the vehicle wire harness.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C1273

Low Output Signal of Rear Speed Sensor RH (Test Mode DTC)

Detected only during Test Mode.

  • Rear speed sensor RH

  • Sensor installation

  • Rear speed sensor rotor RH (Rear axle hub and bearing assembly RH)

C1274

Low Output Signal of Rear Speed Sensor LH (Test Mode DTC)

Detected only during Test Mode.

  • Rear speed sensor LH

  • Sensor installation

  • Rear speed sensor rotor LH (Rear axle hub and bearing assembly LH)

C1277

Abnormal Change in Output Signal of Rear Speed Sensor RH (Test Mode DTC)

Detected only during Test Mode.

Rear speed sensor rotor RH (Rear axle hub and bearing assembly RH)

C1278

Abnormal Change in Output Signal of Rear Speed Sensor LH (Test Mode DTC)

Detected only during Test Mode.

Rear speed sensor rotor LH (Rear axle hub and bearing assembly LH)

C1415

Rear Speed Sensor RH Output Malfunction

Any of the following conditions is detected:

  1. An open in the sensor signal circuit of a malfunctioning area occurs 255 times or more.

  2. At a vehicle speed of 20 km/h (12 mph) or more, noise occurs in the sensor signals of a malfunctioning wheel 75 times or more within 5 seconds.

  3. At a vehicle speed of 10 km/h (6 mph) or more, noise occurs once per rotor rotation for 15 seconds or more.

  • Rear speed sensor RH

  • Speed sensor circuit

  • Sensor installation

  • Rear speed sensor rotor RH (Rear axle hub and bearing assembly RH)

  • Skid control ECU (Brake actuator assembly)

C1416

Rear Speed Sensor LH Output Malfunction

Any of the following conditions is detected:

  1. An open in the sensor signal circuit of a malfunctioning area occurs 255 times or more.

  2. At a vehicle speed of 20 km/h (12 mph) or more, noise occurs in the sensor signals of a malfunctioning wheel 75 times or more within 5 seconds.

  3. At a vehicle speed of 10 km/h (6 mph) or more, noise occurs once per rotor rotation for 15 seconds or more.

  • Rear speed sensor LH

  • Speed sensor circuit

  • Sensor installation

  • Rear speed sensor rotor LH (Rear axle hub and bearing assembly LH)

  • Skid control ECU (Brake actuator assembly)
Tip:

for C1415 and C1416: Even after the trouble areas are repaired, the ABS warning light will not go off unless the following operations are performed.

  1. Drive the vehicle at 20 km/h (12 mph) for 30 seconds or more and check that the ABS warning light goes off.

  2. Clear the DTCs.

Tip:

  • DTC C1415 is for the rear speed sensor RH.

  • DTC C1416 is for the rear speed sensor LH.

WIRING DIAGRAM

C266976E09

PROCEDURE

  1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)

    1. Using the GTS, check for any momentary interruption in the wire harness and connector corresponding to a DTC.

      Click here

      Chassis > ABS/VSC/TRC > Data List

      Tester Display

      Measurement Item

      Range

      Normal Condition

      Diagnostic Note

      RR Speed Open

      Rear speed sensor RH open detection

      Error or Normal

      Error: Momentary interruption

      Normal: Normal

      -

      RL Speed Open

      Rear speed sensor LH open detection

      Error or Normal

      Error: Momentary interruption

      Normal: Normal

      -

      Chassis > ABS/VSC/TRC > Data List

      Tester Display

      RR Speed Open

      RL Speed Open

      OK

      There are no momentary interruptions.

      Tip:

      Perform the above inspection before removing the sensor and connector.

    Result

    Proceed to

    OK

    NG
    NG

    CHECK REAR SPEED SENSOR INSTALLATIONClick here

    OK

  2. READ VALUE USING GTS (REAR SPEED SENSOR)

    1. Turn the ignition switch off.

    2. Connect the GTS to the DLC3.

    3. Start the engine.

    4. Select the Data List using the GTS.

      Click here

      Chassis > ABS/VSC/TRC > Data List

      Tester Display

      Measurement Item

      Range

      Normal Condition

      Diagnostic Note

      RR Wheel Speed

      Rear wheel speed sensor RH reading

      Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph)

      Vehicle stopped: 0 km/h (0 mph)

      When driving at constant speed: No large fluctuations

      RL Wheel Speed

      Rear wheel speed sensor LH reading

      Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph)

      Vehicle stopped: 0 km/h (0 mph)

      When driving at constant speed: No large fluctuations

      Chassis > ABS/VSC/TRC > Data List

      Tester Display

      RR Wheel Speed

      RL Wheel Speed

    5. Check the speed value output from the speed sensor displayed on the GTS.

      Tip:

      Factors that affect the indicated vehicle speed include tire size, tire pressure, and tire wear. The speed indicated on the speedometer has an allowable margin of error. This can be tested using a speedometer tester (calibrated chassis dynamometer). For details about testing and the margin of error, see the reference chart.

      Click hereClick here

      OK

      The speed value output from the speed sensor displayed on the GTS is similar to the speed indicated on the speedometer.

    Result

    Proceed to

    OK

    NG
    NG

    CHECK REAR SPEED SENSOR INSTALLATIONClick here

    OK

  3. RECONFIRM DTC

    1. Turn the ignition switch off.

    2. Clear the DTCs.

      Click here

      Chassis > ABS/VSC/TRC > Clear DTCs

    3. Turn the ignition switch off.

    4. Start the engine.

    5. Perform a road test.

    6. Check if the same DTC is output.

      Click here

      Chassis > ABS/VSC/TRC > Trouble Codes

      Result

      Result

      Proceed to

      DTCs C1415 and C1416 are not output.

      A

      DTCs C1415 and/or C1416 are output.

      B
      Tip:

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts.

      Click here

    A

    USE SIMULATION METHOD TO CHECK

    Click hereClick hereClick here

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY

    Click hereClick here

  4. CHECK REAR SPEED SENSOR INSTALLATION

    1. C210569C04

      *1

      Rear Speed Sensor

      *a

      Correct

      *b

      Incorrect

      *c

      No clearance

      Turn the ignition switch off.

    2. Check the speed sensor installation.

      OK

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

    Result

    Proceed to

    OK

    NG
    NG

    INSTALL REAR SPEED SENSOR CORRECTLY

    Click here

    OK

  5. INSPECT SKID CONTROL SENSOR WIRE

    1. C269033C05

      *A

      RH

      *B

      LH

      *a

      Front view of Skid Control Sensor Wire

      *b

      Front view of wire harness connector

      (to Sensor Side Connector)

      *c

      Front view of wire harness connector

      (to Vehicle Side Connector)

      Turn the ignition switch off.

    2. Make sure that there is no looseness at the locking part and the connecting part of the connectors.

    3. Remove the skid control sensor wire.

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

      Standard Resistance

      Table 1. for RH

      Tester Connection

      Condition

      Specified Condition

      h1-2 (RR+) - hL1-1 (RR+)

      Always

      Below 1 Ω

      h1-2 (RR+) - hL1-2 (RR-)

      Always

      10 kΩ or higher

      h1-2 (RR+) or hL1-1 (RR+) - Body ground

      Always

      10 kΩ or higher

      h1-1 (RR-) - hL1-2 (RR-)

      Always

      Below 1 Ω

      h1-1 (RR-) - hL1-1 (RR+)

      Always

      10 kΩ or higher

      h1-1 (RR-) or hL1-2 (RR-) - Body ground

      Always

      10 kΩ or higher
      Table 2. for LH

      Tester Connection

      Condition

      Specified Condition

      j1-2 (RL+) - jL1-1 (RL+)

      Always

      Below 1 Ω

      j1-2 (RL+) - jL1-2 (RL-)

      Always

      10 kΩ or higher

      j1-2 (RL+) or jL1-1 (RL+) - Body ground

      Always

      10 kΩ or higher

      j1-1 (RL-) - jL1-2 (RL-)

      Always

      Below 1 Ω

      j1-1 (RL-) - jL1-1 (RL+)

      Always

      10 kΩ or higher

      j1-1 (RL-) or jL1-2 (RL-) - Body ground

      Always

      10 kΩ or higher
      Note:

      Check the speed sensor signal after replacement.

      Click here

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE SKID CONTROL SENSOR WIRE

    Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - SKID CONTROL SENSOR WIRE)

    1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

    2. Disconnect the A124 skid control ECU (brake actuator assembly) connector.

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

      Standard Resistance

      Table 3. for RH

      Tester Connection

      Condition

      Specified Condition

      A124-17 (RR+) - hL1-1 (RR+)

      Always

      Below 1 Ω

      A124-17 (RR+) or hL1-1 (RR+) - Body ground

      Always

      10 kΩ or higher

      A124-16 (RR-) - hL1-2 (RR-)

      Always

      Below 1 Ω

      A124-16 (RR-) or hL1-2 (RR-) - Body ground

      Always

      10 kΩ or higher
      Table 4. for LH

      Tester Connection

      Condition

      Specified Condition

      A124-5 (RL+) - jL1-1 (RL+)

      Always

      Below 1 Ω

      A124-5 (RL+) or jL1-1 (RL+) - Body ground

      Always

      10 kΩ or higher

      A124-4 (RL-) - jL1-2 (RL-)

      Always

      Below 1 Ω

      A124-4 (RL-) or jL1-2 (RL-) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. INSPECT BRAKE ACTUATOR ASSEMBLY (SENSOR INPUT)

    1. C269034C10

      *a

      Front view of wire harness connector

      (to Skid Control Sensor Wire)

      Reconnect the A124 skid control ECU (brake actuator assembly) connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage

      Table 5. for RH

      Tester Connection

      Condition

      Specified Condition

      hL1-1 (RR+) - Body ground

      Ignition switch ON

      5.7 to 14 V
      Table 6. for LH

      Tester Connection

      Condition

      Specified Condition

      jL1-1 (RL+) - Body ground

      Ignition switch ON

      5.7 to 14 V
      Note:

      Check the speed sensor signal after replacement.

      Click here

      Tip:

      • The rear speed sensor rotor is incorporated into the rear axle hub and bearing assembly.

        If the rear speed sensor rotor needs to be replaced, replace the rear axle hub and bearing assembly with rear speed sensor.

      • If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts.

        Click here

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE REAR AXLE HUB AND BEARING ASSEMBLY WITH REAR SPEED SENSOR

    Click here

    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY

    Click hereClick here