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:


  • "Skid Control (ABS/VSC/TRAC)" is not displayed on the CAN Bus Check screen of the GTS

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

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  • Skid control ECU assembly branch line or connector

  • Power source circuit of skid control ECU assembly

  • Skid control ECU assembly ground circuit

  • Skid control ECU assembly

WIRING DIAGRAM

B004GBKE01
B004GBKE02

CAUTION / NOTICE / HINT

Note


  • 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.

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

  • DTC check procedure: Turn the power switch on (IG), turn the cruise control main switch on, wait at least 60 seconds and then drive the vehicle at a speed of 36 km/h (22 mph) or more for 4.83 seconds 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.

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

Tech Tips


  • Operating the power switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.

  • 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 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 / Trouble Codes.


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTC C1242 is not output A
      DTC C1242 is output B

    B

    GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here

    A

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


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

    2. Disconnect the A23 skid control ECU assembly connector.

    3. B004GDMC08
      *a

      Front view of wire harness connector

      (to Skid Control ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A23-30 (CA1H) - A23-29 (CA1L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. Disconnect the A22 skid control ECU assembly connector.

    2. B004FTAC35
      *a

      Front view of wire harness connector

      (to Skid Control ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A22-1 (GND) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω
      A23-1 (GND4) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω

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

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A22-29 (+BI3) - Body ground Power switch off 11 to 14 V
      A22-43 (+BI1) - Body ground Power switch off 11 to 14 V
      A22-46 (IG1) - Body ground Power switch on (IG) 11 to 14 V
      A23-22 (+BI4) - Body ground Power switch off 11 to 14 V
      A23-38 (+BI2) - Body ground Power switch off 11 to 14 V
      A23-46 (IG2) - 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 SKID CONTROL ECU ASSEMBLY Click here

    B

    REPLACE SKID CONTROL ECU ASSEMBLY Click here

    C

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