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CAN COMMUNICATION SYSTEM Check Bus 1 Lines for Short Circuit

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DTC Code DTC Name
  Check Bus 1 Lines for Short Circuit
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DESCRIPTION

There may be a short circuit between the CAN main bus lines and/or CAN branch lines when the resistance between terminals 18 (CA4H) and 17 (CA4L) of the central gateway ECU (network gateway ECU) is below 54 Ω.

Symptom Trouble Area
Resistance between terminals 18 (CA4H) and 17 (CA4L) of the central gateway ECU (network gateway ECU) is below 54 Ω.

  • Short in CAN main bus wire

  • Short in CAN branch wire

  • Central gateway ECU (network gateway ECU)

  • Object recognition camera*1

  • Forward recognition camera*2

  • Driving support ECU assembly*1, *2

  • Millimeter wave radar sensor assembly*1, *2

  • Front side radar sensor RH*1

  • Seat belt control ECU*1

  • Parking assist ECU*3

  • Clearance warning ECU assembly

  • Rear television camera assembly

  • Blind spot monitor sensor RH*4

  • No. 3 CAN junction terminal

  • No. 9 CAN junction terminal

  • No. 6 CAN junction connector

  • No. 7 CAN junction connector

  • No. 16 CAN junction connector
*1: w/ Pre-collision System (for Stereo Camera Type) *2: w/ Pre-collision System (for Mono Camera Type) *3: w/ Panoramic View Monitor System *4: w/ Blind Spot Monitor System
B004WN7E07
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WIRING DIAGRAM

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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 power 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 (-) 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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  • Some parts must be initialized and set when replacing or removing and installing parts.

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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 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 the 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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Tip:

  • Before disconnecting related connectors for inspection, push in on each connector body to check that the connector is not loose or disconnected.

  • When a connector is disconnected, check that the terminals and connector body are not cracked, deformed or corroded.

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PROCEDURE


  1. Click here

    CHECK FOR SHORT IN CAN BUS WIRE (NO. 6 CAN JUNCTION CONNECTOR)


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

    2. Disconnect the G125 No. 6 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      G125-7 (CANH) - G125-1 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 16 CAN junction connector
      G125-8 (CANH) - G125-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Driving support ECU assembly*1, *3
      G125-9 (CANH) - G125-3 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Millimeter wave radar sensor assembly*3
      G125-10 (CANH) - G125-4 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 7 CAN junction connector
      G125-5 (CANH) - G125-11 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher

      • Central gateway ECU (network gateway ECU)*1

      • Driving support ECU assembly*2, *3
      G125-12 (CANH) - G125-6 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Parking assist ECU*4
      *1: for RHD *2: for LHD *3: w/ Pre-collision System *4: w/ Panoramic View Monitor System
      Result
      Result Proceed to
      OK A
      NG (Central gateway ECU [network gateway ECU] CAN branch wire) B
      NG (No. 16 CAN junction connector CAN main wire) C
      NG (No. 7 CAN junction connector CAN main wire) D
      NG (Wire to ECU or sensor) E

  2. Click here

    CHECK FOR SHORT IN CAN BUS WIRES (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 6 CAN JUNCTION CONNECTOR)


    1. Reconnect the G125 No. 6 CAN junction connector.

    2. Disconnect the G66 central gateway ECU (network gateway ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G66-18 (CA4H) - G66-17 (CA4L) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    • OK

      REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU)Click here

    • NG

      REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 6 CAN JUNCTION CONNECTOR)

  3. Click here

    CHECK FOR SHORT IN CAN BUS WIRES (NO. 16 CAN JUNCTION CONNECTOR)


    1. Reconnect the G125 No. 6 CAN junction connector.

    2. Disconnect the L123 No. 16 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      L123-1 (CANH) - L123-11 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 6 CAN junction connector
      L123-2 (CANH) - L123-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 3 CAN junction terminal
      L123-3 (CANH) - L123-13 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Clearance warning ECU assembly
      L123-5 (CANH) - L123-15 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Rear television camera assembly
      L123-6 (CANH) - L123-16 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Blind spot monitor sensor RH*1
      L123-7 (CANH) - L123-17 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Seat belt control ECU*2
      *1: w/ Blind Spot Monitor System *2: w/ Pre-collision System (for Stereo Camera Type)
      Result
      Result Proceed to
      OK A
      NG (No. 3 CAN junction terminal CAN main wire) B
      NG (No. 6 CAN junction connector CAN main wire) C
      NG (Wire to ECU or sensor) D

    • A

      REPLACE NO. 16 CAN JUNCTION CONNECTOR

    • BClick here
    • C

      REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 16 CAN JUNCTION CONNECTOR - NO. 6 CAN JUNCTION CONNECTOR)

    • DClick here

      GO TO STEP 8

  4. Click here

    CHECK FOR SHORT IN CAN BUS WIRE (NO. 3 CAN JUNCTION TERMINAL - NO. 16 CAN JUNCTION CONNECTOR)


    1. Reconnect the L123 No. 16 CAN junction connector.

    2. Disconnect the L126 No. 3 CAN junction terminal connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L126-3 (CANH) - L126-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    • OK

      REPLACE NO. 3 CAN JUNCTION TERMINAL

    • NG

      REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 3 CAN JUNCTION TERMINAL - NO. 16 CAN JUNCTION CONNECTOR)

  5. Click here

    CHECK FOR SHORT IN CAN BUS WIRES (NO. 7 CAN JUNCTION CONNECTOR)


    1. Reconnect the G125 No. 6 CAN junction connector.

    2. Disconnect the G126 No. 7 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      G126-7 (CANH) - G126-1 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Central gateway ECU (network gateway ECU)*1
      G126-8 (CANH) - G126-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 9 CAN junction terminal
      G126-9 (CANH) - G126-3 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher

      • Forward recognition camera*2

      • Object recognition camera*3
      G126-10 (CANH) - G126-4 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Swing grille actuator assembly
      G126-11 (CANH) - G126-5 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Front side radar sensor RH*3
      G126-12 (CANH) - G126-6 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 6 CAN junction connector
      *1: for LHD *2: w/ Pre-collision System (for Mono Camera Type) *3: w/ Pre-collision System (for Stereo Camera Type)
      Result
      Result Proceed to
      OK A
      NG (Central gateway ECU [network gateway ECU] CAN branch wire) B
      NG (No. 9 CAN junction terminal CAN main wire) C
      NG (No. 6 CAN junction connector CAN main wire) D
      NG (Wire to ECU or sensor) E

    • A

      REPLACE NO. 7 CAN JUNCTION CONNECTOR

    • BClick here
    • CClick here
    • D

      REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 7 CAN JUNCTION CONNECTOR - NO. 6 CAN JUNCTION CONNECTOR)

    • EClick here
  6. Click here

    CHECK FOR SHORT IN CAN BUS WIRES (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 7 CAN JUNCTION CONNECTOR)


    1. Reconnect the G126 No. 7 CAN junction connector.

    2. Disconnect the G66 central gateway ECU (network gateway ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G66-18 (CA4H) - G66-17 (CA4L) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    • OK

      REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU)Click here

    • NG

      REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 7 CAN JUNCTION CONNECTOR)

  7. Click here

    CHECK FOR SHORT IN CAN BUS WIRE (NO. 9 CAN JUNCTION TERMINAL - NO. 7 CAN JUNCTION CONNECTOR)


    1. Reconnect the G126 No. 7 CAN junction connector.

    2. Disconnect the G127 No. 9 CAN junction terminal connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G129-3 (CANH) - G129-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    • OK

      REPLACE NO. 9 CAN JUNCTION TERMINAL

    • NG

      REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 9 CAN JUNCTION TERMINAL - NO. 7 CAN JUNCTION CONNECTOR)

  8. Click here

    CHECK FOR SHORT IN CAN BUS WIRES (ECU, SENSOR)


    1. Reconnect all wire harness connectors.

    2. Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the short circuited branch wire is connected.

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    3. B004T3JC19
      *a

      Component with harness connected

      (Central Gateway ECU [Network Gateway ECU])

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G66-18 (CA4H) - G66-17 (CA4L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω
      Tip:

      • If the resistance becomes normal (between 54 and 69 Ω) when the connector is disconnected from the ECU or sensor, there may be a short in the ECU or sensor.

      • If the resistance does not become normal when the connector is disconnected from the ECU or sensor, check for a short in the wire harness and repair or replace the wire harness or connector if necessary.

      Result
      Proceed to
      OK
      NG

    • OK

      REPLACE ECU OR SENSOR

    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR