CAN COMMUNICATION SYSTEM(w/o Central Gateway ECU) 4WD Control ECU Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
4WD Control ECU Communication Stop Mode

Either condition is met:


  • "Four Wheel Drive Control" is not displayed on "CAN Bus Check".

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  • Communication system DTCs (DTCs that start with U) that are output correspond to "4WD Control ECU Communication Stop Mode" in "DTC Combination Table"

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  • 4 wheel drive control ECU CAN branch wire or connector

  • Power source circuit of 4 wheel drive control ECU

  • 4 wheel drive control ECU ground circuit

  • 4 wheel drive control ECU

WIRING DIAGRAM

B001G98E01

CAUTION / NOTICE / HINT

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

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.

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  • Before measuring the resistance of the CAN bus, turn the ignition 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 ignition 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.

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

  • DTC check procedure: Turn the ignition switch to ON, wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more.

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

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Tech Tips


  • Operating the ignition 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 (4 WHEEL DRIVE CONTROL ECU BRANCH WIRE)


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

    2. B001EY7C01
      *a

      Rear view of wire harness connector

      (to 4 Wheel Drive Control ECU)

      Disconnect the 4 wheel drive control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G53-20 (CANH) - G53-40 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR

    OK

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. Disconnect the 4 wheel drive control ECU connector.

      B001H64C02
      *a

      Front view of wire harness connector

      (to 4 Wheel Drive Control ECU)

      		 - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G54-10 (GND) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω

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

      Note

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

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      G54-21 (+B) - Body ground Always 11 to 14 V
      G54-4 (IG) - Body ground Ignition switch ON 11 to 14 V
      Ignition switch off Below 1 V

    OK

    REPLACE 4 WHEEL DRIVE CONTROL ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)