CAN COMMUNICATION SYSTEM(for RHD) Electric Parking Brake ECU Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Electric Parking Brake ECU Communication Stop Mode

Either condition is met:


  • "Electric Parking Brake" is not displayed on "CAN Bus Check".

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

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  • Power source circuit of parking brake ECU assembly

  • Parking brake ECU assembly ground circuit

  • Parking brake ECU assembly CAN branch wire or connector

  • Parking brake ECU assembly

WIRING DIAGRAM

A0001C7E02

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, 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) and wait at least 300 seconds, and then drive the vehicle at a speed of 36 km/h (22 mph) or more for 7 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 FOR OPEN IN CAN BUS WIRE (PARKING BRAKE ECU ASSEMBLY BRANCH WIRE)


    1. B002JPGC04
      *a

      Front view of wire harness connector

      (to Parking Brake ECU Assembly)

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

    2. Disconnect the parking brake ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q24-11 (CANH) - Q24-1 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (PARKING BRAKE ECU ASSEMBLY)

    OK

  2. CHECK HARNESS AND CONNECTOR (PARKING BRAKE ECU ASSEMBLY - BATTERY AND BODY GROUND)


    1. A00008IC03
      *a

      Front view of wire harness connector

      (to Parking Brake ECU Assembly)

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

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

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    2. Disconnect the parking brake ECU assembly connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      Q25-7 (+B) - Body ground Power switch off 11 to 14 V
      Q25-12 (+B2) - Body ground Power switch off 11 to 14 V
      Q24-5 (IG) - Body ground Power switch on (IG) 11 to 14 V
      Q24-3 (BECU) - Body ground Power switch off 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q25-9 (GND1) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE PARKING BRAKE ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR