CAN COMMUNICATION SYSTEM Skid Control ECU Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
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.

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

  • Skid control ECU (brake booster with master cylinder assembly) branch line or connector

  • Power source circuit of skid control ECU (brake booster with master cylinder assembly)

  • Skid control ECU (brake booster with master cylinder assembly)

WIRING DIAGRAM

B001MRDE21

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 power 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 (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

    Click here

  • 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.

    Click here

  • 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 DTC (BRAKE CONTROL SYSTEM)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Chassis / ABS/VSC/TRC / DTC.

      OK
      DTC C1241 is not output.

    NG

    GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here

    OK

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


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

    2. B001LH5E02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

      Disconnect the A61 skid control ECU (brake booster with master cylinder assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A61-37 (CA1H) - A61-38 (CA1L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (SKID CONTROL ECU)

    OK

  3. CHECK HARNESS AND CONNECTOR (GROUND TERMINAL)


    1. B001L7UC03
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A61-28 (GND) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND TERMINAL)

    OK

  4. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)


    1. Reconnect the cable to the negative (-) auxiliary battery terminal.

    2. B001L7UC02
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A61-16 (IG1) - Body ground Power switch on (IG) 11 to 14 V
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (SKID CONTROL ECU) Click here

    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (SKID CONTROL ECU) Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)