ANTI-LOCK BRAKE SYSTEM, Diagnostic DTC:C1243, C1245, C1279

DTC Code DTC Name
C1243 Acceleration Sensor Stuck Malfunction
C1245 Acceleration Sensor Output Malfunction
C1279 Acceleration Sensor Output Voltage Malfunction (Test Mode DTC)

DESCRIPTION

The skid control ECU (brake actuator assembly) receives signals from the acceleration sensor (airbag sensor assembly) via the CAN communication system.

The airbag sensor assembly has a built-in acceleration sensor and detects the vehicle's condition using 2 circuits (GL1, GL2).

If there is trouble in the bus lines between the acceleration sensor (airbag sensor assembly) and the CAN communication system, DTCs U0123 (malfunction in CAN communication with the yaw rate sensor) and U0124 (malfunction in CAN communication with the acceleration sensor) are stored.

These DTCs are also stored when calibration has not been completed.

DTC C1279 can be cleared when the acceleration sensor (airbag sensor assembly) sends an acceleration signal or test mode ends. DTC C1279 is stored only in test mode.

DTC Code DTC Detection Condition Trouble Area
C1243 While the vehicle speed changes from 30 km/h (19 mph) to 0 km/h (0 mph), the condition that the values of GL1 and GL2 do not change by 0.0294 G or more occurs 16 times or more.

  • IGN fuse

  • Acceleration sensor (Airbag sensor assembly)

  • Acceleration sensor (Airbag sensor assembly) circuit
C1245 At a vehicle speed of 30 km/h (19 mph) or more, the difference between the forward and backward G calculated from the acceleration sensor value and that calculated from the vehicle speed exceeds 0.35 G for 60 seconds or more.

  • IGN fuse

  • Acceleration sensor (Airbag sensor assembly)

  • Acceleration sensor (Airbag sensor assembly) circuit

  • Sensor installation
C1279 Stored only during test mode.

  • Acceleration sensor (Airbag sensor assembly)

  • Sensor installation

WIRING DIAGRAM

B001CP9E26
*1 Acceleration Sensor (Airbag Sensor Assembly)
*2 Skid Control ECU (Brake Actuator Assembly)
*3 CAN Communication Line

CAUTION / NOTICE / HINT

Note


  • When replacing the acceleration sensor (airbag sensor assembly) , perform calibration Click here.

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Tech Tips

When DTC U0124 is output together with DTC C1243 and/or C1245, inspect and repair the trouble areas indicated by DTC U0124 first Click here.

PROCEDURE


  1. CHECK DTC


    1. Clear the DTCs Click here.

    2. Turn the ignition switch off.

    3. At a speed of 30 km/h (19 mph) or more, drive the vehicle, turn the steering wheel and decelerate (depress the brake pedal) the vehicle.

    4. Turn the ignition switch to ON again and check that no CAN communication system DTC is output Click here.

      Result
      Result Proceed to
      DTC output (relating to yaw rate and acceleration sensor) A
      DTC output (relating to CAN communication system) B

    B

    GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) Click here

    A

  2. CHECK AIRBAG SENSOR ASSEMBLY INSTALLATION


    1. Turn the ignition switch off.

    2. Check that the yaw rate and acceleration sensor (airbag sensor assembly) has been installed properly Click here.

      OK
      The sensor is tightened to the specified torque.
      The sensor is not tilted.

    NG

    INSTALL AIRBAG SENSOR ASSEMBLY CORRECTLY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (IG2, E1, E2)

    Note


    • After turning the engine switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work Click here.

    • When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.


    1. Turn the ignition switch off.

    2. Disconnect the cable from the negative (-) battery terminal, and wait for at least 90 seconds.

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

    4. Disconnect the G1 acceleration sensor (airbag sensor assembly) connector.

    5. Connect the cable to the negative (-) battery terminal, and wait for at least 2 seconds.

    6. Turn the ignition switch to ON.

    7. Operate all the components of the electrical system (defogger, wipers, headlights, heater blower, etc.).

    8. B001HJ1E28
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Acceleration Sensor (Airbag Sensor Assembly))

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G1-21 (IG2) - Body ground Ignition switch ON 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G1-25 (E1) - Body ground Always Below 1 Ω
      G1-26 (E2) - Body ground Always Below 1 Ω
      Result
      Result Proceed to
      OK (When troubleshooting in accordance with diagnostic trouble code chart) A
      OK (When troubleshooting in accordance with problem symptoms table) B
      NG C

      Note

      Check the acceleration sensor signal after replacement Click here.


    A

    REPLACE AIRBAG SENSOR ASSEMBLY Click here

    B

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR