ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1234, C1243, C1244, C1245, C1279, C1381

DTC Code DTC Name
C1234 Yaw Rate Sensor
C1243 Deceleration Sensor Stuck
C1244 Open or Short Circuit in Deceleration Sensor Circuit
C1245 Abnormal Output in Deceleration Sensor
C1279 Abnormal Output Voltage in Deceleration Sensor (Test Mode DTC)
C1381 Abnormal Power Supply Voltage in Yaw Rate and/or Deceleration Sensor

DESCRIPTION

The skid control ECU receives signals from the yaw rate and acceleration sensor (airbag ECU assembly) via the CAN communication system.

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

If there are any problems in the bus lines between the yaw rate and acceleration sensor (airbag ECU assembly) and the CAN communication system, DTCs U0123 (Lost Communication With Yaw Rate Sensor Module) and U0124 (Lost Communication With Lateral Acceleration Sensor Module) are output.

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

DTC C1279 will be cleared when the yaw rate and acceleration sensor (airbag ECU assembly) sends a yaw rate and/or acceleration signal or when Test Mode ends. DTC C1279 is output only in Test Mode.

DTC Code INF Code DTC Detection Condition Trouble Area
C1234 711 While yaw rate sensor communication is enabled, a malfunction signal output is received during the sensor self-check (Sensor 1 (GL1) malfunction). Yaw rate sensor (Airbag ECU assembly) internal malfunction
↑ 712 While yaw rate sensor communication is enabled, a malfunction signal output is received during the sensor self-check (Sensor 2 (GL2) malfunction). ↑
↑ 713 While yaw rate sensor communication is enabled, a malfunction signal output is received during the sensor self-check (Zero point calibration malfunction). ↑
↑ 714 While yaw rate sensor communication is enabled, a malfunction signal output is received during the sensor self-check (Two-value comparison malfunction). ↑
C1243 561 An acceleration sensor malfunction occurs 16 times or more when the vehicle speed drops from above 30 km/h (19 mph) to 0 km/h (0 mph). Acceleration sensor (Airbag ECU assembly) internal stuck malfunction
↑

562

563

564

565

 A stuck acceleration sensor value is determined. ↑
C1244 571

Either of the following is detected:


  1. Difference between GL1 and GL2 does not become less than 0.4 G for 60 seconds or more after reaching 0.6 G when the vehicle is stopped.

  2. A malfunction signal from the acceleration sensor is received.

  • Acceleration sensor (Airbag ECU assembly) installed improperly

  • Acceleration sensor (Airbag ECU assembly)
C1245 581 Difference between longitudinal G calculated from the acceleration sensor value and that calculated from the vehicle speed exceeds 0.35 G for 60 seconds or more.

  • Acceleration sensor (Airbag ECU assembly) installed improperly

  • Acceleration sensor (Airbag ECU assembly)
C1381 601 While acceleration sensor communication is enabled, a supply voltage malfunction signal is received from the sensor for 10 seconds.

  • Acceleration sensor (Airbag ECU assembly) supply voltage shut down

  • Acceleration sensor (Airbag ECU assembly)

  • Brake booster with master cylinder (Skid control ECU)
C1279 - Detected only during Test Mode.

  • Sensor installation

  • Acceleration sensor (Airbag ECU assembly)

WIRING DIAGRAM

B005XQ7E27
*1 from IG2 Relay
*2 Yaw Rate and Acceleration Sensor (Airbag ECU Assembly)
*3 Brake Booster with Master Cylinder

CAUTION / NOTICE / HINT

Note

When replacing the yaw rate and acceleration sensor (airbag ECU assembly), perform zero point calibration Click here.

Tech Tips

When U0123 and/or U0124 is output together with C1234, C1243, C1244, C1245, and/or C1381, inspect and repair the trouble areas indicated by U0123 and/or U0124 first Click here.

PROCEDURE


  1. CHECK DTC


    1. Clear the DTCs Click here.

    2. Turn the power switch off (lock).

    3. Turn the power switch on (ready).

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

    5. Turn the power switch on (IG) again and check that no CAN communication system DTC is output (See page for with Central Gateway ECU or Click here for without Central Gateway ECU).

    6. Check if DTC C1210 (Zero Point Calibration of Yaw Rate Sensor undone) or C1336 (Zero Point Calibration of Deceleration Sensor undone) is output Click here.

      Result
      Result Proceed to
      DTCs (C1210, C1336 and CAN communication system DTC) are not output A
      CAN communication system DTC is output (w/ Central Gateway ECU) B
      CAN communication system DTC is output (w/o Central Gateway ECU) C
      DTCs (C1210 and/or C1336) are output D

    B

    INSPECT CAN COMMUNICATION SYSTEM Click here

    C

    INSPECT CAN COMMUNICATION SYSTEM Click here

    D

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

    A

  2. CHECK AIRBAG ECU ASSEMBLY


    1. Turn the power switch off (lock).

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

      OK
      The airbag ECU assembly is tightened to the specified torque.
      The airbag ECU assembly is not tilted.

    NG

    INSTALL AIRBAG ECU ASSEMBLY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (IG2 TERMINAL)


    1. B005ZCEE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Yaw Rate and Acceleration Sensor (Airbag ECU Assembly))

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

    2. Disconnect the yaw rate and acceleration sensor (airbag ECU assembly) connector.

    3. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      L16-21 (IG2) - Body ground Power switch on (IG) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IG2 CIRCUIT)

    OK

  4. CHECK HARNESS AND CONNECTOR (E TERMINAL)


    1. B005ZKNE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Yaw Rate and Acceleration Sensor (Airbag ECU Assembly))

      Turn the power switch off (lock).

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L16-25 (E1) - Body ground Always Below 1 Ω
      L16-26 (E2) - Body ground Always Below 1 Ω

      Note

      Check the yaw rate and acceleration sensor signal after replacement Click here.

      Tech Tips

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


    OK

    REPLACE AIRBAG ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (E CIRCUIT)