CAN COMMUNICATION SYSTEM(for LHD with Central Gateway ECU) Open in Bus 3 Main Bus Line

DESCRIPTION

There may be an open circuit in one of the bus 3 CAN main wires when the resistance between terminals 6 (CA3H) and 21 (CA3L) of the central gateway ECU is 70 Ω or higher.

Symptom Trouble Area
Resistance between terminals 6 (CA3H) and 21 (CA3L) of central gateway ECU is 70 Ω or higher.

  • CAN main wire or connector

  • Central gateway ECU

  • No. 8 CAN junction connector

  • No. 13 CAN junction connector*
*: w/ Telematics Transceiver

This malfunction is not related to the lines of a bus 3 branch or to ECUs or sensors connected to a bus 3 branch.

WIRING DIAGRAM

Figure 1. w/o Telematics Transceiver:

A01V7MTE03
*a CAYH
*b CAYL
*c No. 8 CAN Junction Connector
*d Central Gateway ECU

Figure 2. w/ Telematics Transceiver:

A01V9X0E04

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 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.

    Click here

  • 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 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 VEHICLE TYPE


    1. Check vehicle type.

      Result
      Result Proceed to
      w/o Telematics Transceiver A
      w/ Telematics Transceiver B

    B

    CHECK FOR OPEN IN CAN BUS WIRE (NO. 8 CAN JUNCTION CONNECTOR) Click here

    A

  2. CHECK FOR OPEN IN CAN BUS WIRE (NO. 8 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU)


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

      A01V7BPC68
      *a

      Front view of wire harness connector

      (to No. 8 CAN Junction Connector)

      		 - -

    2. Disconnect the No. 8 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G173-3 (CANH) - G173-14 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      G173-4 (CANH) - G173-15 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NO. 8 CAN JUNCTION CONNECTOR

    NG

  3. CONNECT CONNECTOR


    1. Reconnect the G173 No. 8 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  4. CHECK FOR OPEN IN CAN BUS WIRE (CENTRAL GATEWAY ECU)


    1. A01VABCC27
      *a

      Front view of wire harness connector

      (to Central Gateway ECU)

      Disconnect the central gateway ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G170-6 (CA3H) - G170-21 (CA3L) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      G170-19 (CAYH) - G170-20 (CAYL) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE CENTRAL GATEWAY ECU Click here

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (CENTRAL GATEWAY ECU - NO. 8 CAN JUNCTION CONNECTOR)

  5. CHECK FOR OPEN IN CAN BUS WIRE (NO. 8 CAN JUNCTION CONNECTOR)


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

      A01V8NQC05
      *a

      Front view of wire harness connector

      (to No. 8 CAN Junction Connector)

      		 *b to No. 13 CAN Junction Connector
      *c to Central Gateway ECU - -

    2. Disconnect the No. 8 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G173-2 (CANH) - G173-13 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      G173-3 (CANH) - G173-14 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (No. 13 CAN junction connector CAN main wire) B
      NG (Central gateway ECU CAN main wire) C

    A

    REPLACE NO. 8 CAN JUNCTION CONNECTOR

    C

    CONNECT CONNECTOR Click here

    B

  6. CONNECT CONNECTOR


    1. Reconnect the G173 No. 8 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  7. CHECK FOR OPEN IN CAN BUS WIRE (NO. 13 CAN JUNCTION CONNECTOR)


    1. Disconnect the No. 13 CAN junction connector.

      A01V8NQC02
      *a

      Front view of wire harness connector

      (to No. 13 CAN Junction Connector)

      		 *b to Central Gateway ECU
      *c to No. 8 CAN Junction Connector - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      M39-2 (CANH) - M39-13 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      M39-3 (CANH) - M39-14 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (No. 8 CAN junction connector CAN main wire) B
      NG (Central gateway ECU CAN main wire) C

    A

    REPLACE NO. 13 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 13 CAN JUNCTION CONNECTOR - NO. 8 CAN JUNCTION CONNECTOR)

    C

  8. CONNECT CONNECTOR


    1. Reconnect the M39 No. 13 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  9. CHECK FOR OPEN IN CAN BUS WIRE (CENTRAL GATEWAY ECU)


    1. A01V97JC01
      *a

      Front view of wire harness connector

      (to Central Gateway ECU)

      Disconnect the central gateway ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G170-19 (CAYH) - G170-20 (CAYL) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE CENTRAL GATEWAY ECU Click here

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (CENTRAL GATEWAY ECU - NO. 13 CAN JUNCTION CONNECTOR)

  10. CONNECT CONNECTOR


    1. Reconnect the G173 No. 8 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  11. CHECK FOR OPEN IN CAN BUS WIRE (CENTRAL GATEWAY ECU)


    1. A01V97JC02
      *a

      Front view of wire harness connector

      (to Central Gateway ECU)

      Disconnect the central gateway ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G170-6 (CA3H) - G170-21 (CA3L) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE CENTRAL GATEWAY ECU Click here

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (CENTRAL GATEWAY ECU - NO. 8 CAN JUNCTION CONNECTOR)