CAN COMMUNICATION SYSTEM(for RHD) Headlight ECU Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Headlight ECU Communication Stop Mode

Either Condition is met:


  • Communication stop for "Headlight swivel (AFS)" is indicated on the "Communication Bus Check" screen of the GTS Click here.

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

  • Headlight ECU sub-assembly LH CAN branch wire or connector

  • Power source circuit of headlight ECU sub-assembly LH

  • Headlight ECU sub-assembly LH ground circuit

  • Headlight ECU sub-assembly LH

WIRING DIAGRAM

B0019FFE03

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 engine 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 (-) 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 battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work Click here.

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

  • 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 at least 20 seconds.

  • After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed Click here.

Tech Tips


  • Operating the engine switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  • 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 (HEADLIGHT ECU SUB-ASSEMBLY LH CAN BRANCH WIRE)


    1. B0019PZE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Headlight ECU Sub-assembly LH)

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

    2. Disconnect the headlight ECU sub-assembly LH connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A64-24 (CANH) - A64-23 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO HEADLIGHT ECU SUB-ASSEMBLY LH (CANH, CANL)

    OK

  2. CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY LH - BATTERY AND BODY GROUND)


    1. B001B4LE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Headlight ECU Sub-assembly LH)

      Connect the cable to the negative (-) battery terminal.

      Note

      When connecting the cable, some systems need to be initialized after the cable is reconnected Click here.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A64-13 (ECUB) - Body ground Engine switch on (IG) 11 to 14 V
      A64-4 (IG) - Body ground Engine switch on (IG) 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A64-12 (GND) - Body ground Always Below 1 Ω

    OK

    REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR