CAN COMMUNICATION SYSTEM Brake Actuator (Skid Control ECU) Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Brake Actuator (Skid Control ECU) Communication Stop Mode

Either condition is met:


  • Communication stop for "Skid Control (ABS/VSC/TRAC)" is indicated on the "Communication Bus Check" screen of the GTS.

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

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  • Skid control ECU (brake actuator assembly) main line or connector

  • Skid control ECU (brake actuator assembly) branch line or connector

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

  • Skid control ECU (brake actuator assembly) ground circuit

  • Skid control ECU (brake actuator assembly)

WIRING DIAGRAM

B0077MDE01
B0072Q0E01

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 or any 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 negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

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

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

Tech Tips


  • Before disconnecting related connectors for inspection, push in on each connector body to check that the connector is not loose or disconnected.

  • When a connector is disconnected, check that the terminals and connector body are not cracked, deformed or corroded.

PROCEDURE


  1. CHECK VEHICLE TYPE


    1. Check vehicle type.

      Result
      Result Proceed to
      w/o VGRS System A
      w/ VGRS System B

    B

    CHECK FOR OPEN IN CAN BUS LINES (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) BRANCH LINE) Click here

    A

  2. CHECK FOR OPEN IN CAN BUS LINES (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) BRANCH LINE)


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

    2. Disconnect the A94 skid control ECU (brake actuator assembly) connector.

    3. B00760MC18
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A94-22 (CANH) - A94-10 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      Result
      Result
      OK
      NG

    NG

    REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY))

    OK

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. B00760MC19
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A94-1 (GND2) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω
      A94-25 (GND1) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω

    2. Reconnect the cable to the negative (-) battery terminal.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A94-13 (BM) - Body ground Always 11 to 14 V
      A94-38 (+BS) - Body ground Always 11 to 14 V
      A94-12 (IG1) - Body ground Engine switch on (IG) 11 to 14 V
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B

      • NG (except IG1 signal circuit)

      • NG (for IG1 signal circuit (w/o Stop and Start System))

      		 C
      NG (for IG1 signal circuit (w/ Stop and Start System)) D

    A

    REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) Click here

    B

    REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    D

    GO TO STOP AND START SYSTEM (FOR BACKUP BOOST CONVERTER CIRCUIT) Click here

  4. CHECK FOR OPEN IN CAN BUS LINES (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) BRANCH LINE)


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

    2. Disconnect the A94 skid control ECU (brake actuator assembly) connector.

    3. B00760MC20
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A94-22 (CANH) - A94-10 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      A94-36 (CA2H) - A94-37 (CA2L) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Result
      OK
      NG

    NG

    REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY))

    OK

  5. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. B00760MC19
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A94-1 (GND2) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω
      A94-25 (GND1) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω

    2. Reconnect the cable to the negative (-) battery terminal.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A94-13 (BM) - Body ground Always 11 to 14 V
      A94-38 (+BS) - Body ground Always 11 to 14 V
      A94-12 (IG1) - Body ground Engine switch on (IG) 11 to 14 V
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

    REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) Click here

    B

    REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)