CAN COMMUNICATION SYSTEM ABS and Traction Actuator (Skid Control ECU) Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
ABS and Traction Actuator (Skid Control ECU) Communication Stop Mode

Either condition is met:


  • "Skid Control (ABS/VSC/TRAC)" is not displayed on the "CAN Bus Check" screen Click here.

  • Communication system DTCs (DTCs that start with U) that are output correspond to "ABS and Traction Actuator (Skid Control ECU) Communication Stop Mode" in "DTC Combination Table" Click here.

  • Brake actuator assembly (skid control ECU) CAN branch wire or connector

  • Power source circuit of brake actuator assembly (skid control ECU)

  • Brake actuator assembly (skid control ECU) ground circuit

  • Brake actuator assembly (skid control ECU)

WIRING DIAGRAM

A002OIME01
A002NB7E01

CAUTION / NOTICE / HINT

Note


  • Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output Click here.

  • Before measuring the resistance of the CAN bus, turn the ignition switch off and leave the vehicle for 1 minute or more without operating the key, switches or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the ignition 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.

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

  • After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

  • After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed Click here.

Tech Tips


  • Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  • Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE


  1. CHECK FOR OPEN IN CAN BUS WIRE (SKID CONTROL ECU CAN BRANCH WIRE)


    1. A002MICE02
      Text in Illustration
      *A for CVT
      *B for Manual Transaxle
      *a

      Front view of wire harness connector

      (to Brake Actuator Assembly [Skid Control ECU])

      Disconnect the cable from the negative (-) battery terminal.

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

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

      Standard Resistance
      for CVT
      Tester Connection Condition Specified Condition
      A78-26 (CANH) - A78-14 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      for Manual Transaxle
      Tester Connection Condition Specified Condition
      A79-2 (CANH) - A79-16 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO SKID CONTROL ECU (CANH, CANL)

    OK

  2. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BATTERY AND BODY GROUND)


    1. A002QUPE02
      Text in Illustration
      *A for CVT
      *B for Manual Transaxle
      *a

      Front view of wire harness connector

      (to Brake Actuator Assembly [Skid Control ECU])

      Connect the cable to the negative (-) battery terminal.

      Note

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

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

      Standard Resistance
      for CVT
      Tester Connection Condition Specified Condition
      A78-13 (GND2) - Body ground Always Below 1 Ω
      A78-38 (GND1) - Body ground Always Below 1 Ω
      for Manual Transaxle
      Tester Connection Condition Specified Condition
      A79-38 (GND2) - Body ground Always Below 1 Ω
      A79-14 (GND1) - Body ground Always Below 1 Ω

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

      Standard Voltage
      for CVT
      Tester Connection Condition Specified Condition
      A78-1 (+BM) - Body ground Always 11 to 14 V
      A78-25 (+BS) - Body ground Always 11 to 14 V
      A78-28 (IG1) - Body ground Ignition switch ON 11 to 14 V
      for Manual Transaxle
      Tester Connection Condition Specified Condition
      A79-15 (+BM) - Body ground Always 11 to 14 V
      A79-1 (+BS) - Body ground Always 11 to 14 V
      Result
      Result Proceed to
      OK (for CVT) A
      OK (for Manual Transaxle) B
      NG C

    A

    REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU) Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    B

  3. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BATTERY)


    1. A002POSE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Brake Actuator Assembly [Skid Control ECU])

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

      Standard Voltage
      w/o Stop and Start System
      Tester Connection Switch Condition Specified Condition
      A79-4 (IG1) - Body ground Ignition switch ON 11 to 14 V
      w/ Stop and Start System
      Tester Connection Switch Condition Specified Condition
      A79-4 (IG1) - Body ground Ignition switch ON 10.5 to 16 V
      Result
      Result Proceed to
      OK A
      NG (w/ Stop and Start System) B
      NG (w/o Stop and Start System) C

    A

    REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU) Click here

    B

    GO TO STOP AND START SYSTEM Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR