CAN COMMUNICATION SYSTEM(for LHD) 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:


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

    Click here

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

    Click here


  • 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

A01UDL7E03

CAUTION / NOTICE / HINT

Note


  • 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.

    Click here

  • 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

  • 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), wait at least 61 seconds, and then drive the vehicle at a speed of 15 km/h (9 mph) or more for 3 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.

    Click here

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

Tech Tips


  • Operating the engine 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 FOR OPEN IN CAN BUS LINES (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) BRANCH LINE)


    1. B006RJYC04
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

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

    2. Disconnect the A50 skid control ECU (brake actuator assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A50-22 (CANH) -A50-10 (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

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. A01UD32C05
      *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
      A50-1 (GND2) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω
      A50-25 (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
      A50-12 (IG1) - Body ground Engine switch on (IG) 11 to 14 V
      A50-13 (BM) - Body ground Always 11 to 14 V
      A50-38 (+BS) - Body ground Always 11 to 14 V
      Result
      Result
      OK
      NG

    OK

    REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)