CAN COMMUNICATION SYSTEM Skid Control ECU Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Skid Control ECU Communication Stop Mode

Any of the following conditions are met:


  • Communication stop for "Skid Control (ABS/VSC/TRAC)" is indicated on "CAN Bus Check".

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

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

  • Brake actuator assembly (skid control ECU) ground circuit

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

  • Brake actuator assembly (skid control ECU)

WIRING DIAGRAM

Figure 1. w/o Stop and Start System:

B005ATCE08

Figure 2. w/ Stop and Start System:

B0057QTE04

CAUTION / NOTICE / HINT

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

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.

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  • Before measuring the resistance of the CAN bus, turn the engine 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 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.

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  • Some parts must be initialized and set when replacing or removing and installing parts.

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

  • DTC check procedure: Turn the engine switch on (IG) and wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more.

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

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Tech Tips


  • Operating the engine 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 (BRAKE ACTUATOR ASSEMBLY [SKID CONTROL ECU] BRANCH WIRE)


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

    2. B005927C04
      *a

      Front view of wire harness connector

      (to Brake Actuator Assembly [Skid Control ECU])

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A36-22 (CANH) - A36-10 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      Result
      Result Proceed to
      OK (w/ Stop and Start System) A
      OK (w/o Stop and Start System) B
      NG C

    B

    CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT) Click here

    C

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR

    A

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. B005927C11
      *a

      Front view of wire harness connector

      (to Brake Actuator Assembly [Skid Control ECU])

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A36-25 (GND1) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω
      A36-1 (GND2) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω

    2. Reconnect 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

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A36-12 (IG1) - Body ground Engine switch on (IG) 10.5 to 16 V
      Engine switch off Below 1 V
      A36-13 (BM) - Body ground Always 11 to 14 V
      A36-38 (+BS) - Body ground Always 11 to 14 V
      Result
      Result Proceed to
      OK A
      NG (IG1 terminal) B
      NG (Other terminal) 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 (POWER SOURCE CIRCUIT)

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. B005927C11
      *a

      Front view of wire harness connector

      (to Brake Actuator Assembly [Skid Control ECU])

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A36-25 (GND1) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω
      A36-1 (GND2) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω

    2. Reconnect 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

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A36-12 (IG1) - Body ground Engine switch on (IG) 11 to 14 V
      Engine switch off Below 1 V
      A36-13 (BM) - Body ground Always 11 to 14 V
      A36-38 (+BS) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU) Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)