CAN COMMUNICATION SYSTEM Check Chassis Local Bus Lines for Short Circuit

DESCRIPTION

There may be a short circuit between the CAN main bus lines and/or CAN branch lines when the resistance between terminals 19 (CAYH) and 20 (CAYL) of the central gateway ECU (network gateway ECU) is below 54 Ω.

Symptom Trouble Area
The resistance between terminals 19 (CAYH) and 20 (CAYL) 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)

  • Rear steering control ECU*1

  • Absorber control ECU

  • Front steering control ECU*2

  • Driving support ECU assembly*3

  • Rack and pinion power steering gear assembly

  • Skid control ECU assembly

  • No. 8 CAN junction connector

  • No. 17 CAN junction connector

  • No. 18 CAN junction connector
*1: w/ Dynamic Rear Steering System
*2: w/ Variable Gear Ratio Steering System
*3: w/ Pre-collision System

WIRING DIAGRAM


  1. for LHD

    B004BYXE04
    B004A7OE04

  2. for RHD

    B004BYXE05
    B004A7OE04

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.

    Click here

  • 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.

    Click here

  • Some parts must be initialized and set when replacing or removing and installing parts.

    Click here

  • 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.

    Click here

Tech Tips


  • 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.

PROCEDURE


  1. CHECK FOR SHORT IN CAN BUS WIRES (SKID CONTROL ECU ASSEMBLY - NO. 8 CAN JUNCTION CONNECTOR)


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

    2. B004CDPC01
      *a

      Front view of wire harness connector

      (to Skid Control ECU Assembly)

      Disconnect the skid control ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A9-10 (CA2H) - A9-11 (CA2L) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    A

    REPLACE SKID CONTROL ECU ASSEMBLY for LHD: REPLACE SKID CONTROL ECU ASSEMBLY Click here
    REPLACE SKID CONTROL ECU ASSEMBLY for RHD: REPLACE SKID CONTROL ECU ASSEMBLY Click here

    C

    CONNECT CONNECTOR Click here

    B

  2. CONNECT CONNECTOR


    1. Reconnect the A9 skid control ECU assembly connector.

      Result
      Proceed to
      NEXT

    NEXT

  3. CHECK FOR SHORT IN CAN BUS WIRES (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 17 CAN JUNCTION CONNECTOR)


    1. B004BXLC16
      *a

      Front view of wire harness connector

      (to Central Gateway ECU [Network Gateway ECU])

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      P59-19 (CAYH) - P59-20 (CAYL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Result
      OK
      NG

    OK

    REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) Click here

    NG

  4. CONNECT CONNECTOR


    1. Reconnect the P59 central gateway ECU (network gateway ECU) connector.

      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK FOR SHORT IN CAN BUS WIRES (NO. 17 CAN JUNCTION CONNECTOR)


    1. B004CJAC20
      *a

      Front view of wire harness connector

      (to No. 17 CAN Junction Connector)
      *b to No. 18 CAN Junction Connector
      *c to Absorber Control ECU
      *d to Central Gateway ECU (Network Gateway ECU)

      Disconnect the No. 17 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      X114-1 (CANH) - X114-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 18 CAN junction connector
      X114-2 (CANH) - X114-13 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Absorber control ECU
      X114-3 (CANH) - X114-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Central gateway ECU (network gateway ECU)
      Result
      Result Proceed to
      OK A
      NG (Central gateway ECU [network gateway ECU] CAN main wire) B
      NG (No. 18 CAN junction connector CAN main wire) C
      NG (Wire to ECU or sensor) D

    A

    REPLACE NO. 17 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 17 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU])

    D

    GO TO STEP 18 Click here

    C

  6. CONNECT CONNECTOR


    1. Reconnect the X114 No. 17 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  7. CHECK FOR SHORT IN CAN BUS WIRES (NO. 18 CAN JUNCTION CONNECTOR)


    1. B004CJAC21
      *a

      Front view of wire harness connector

      (to No. 18 CAN Junction Connector)
      *b to No. 17 CAN Junction Connector
      *c to Rear Steering Control ECU (w/ Dynamic Rear Steering System)
      *d to No. 8 CAN Junction Connector

      Disconnect the No. 18 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      b10-9 (CANH) - b10-20 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 17 CAN junction connector
      b10-10 (CANH) - b10-21 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Rear steering control ECU*
      b10-11 (CANH) - b10-22 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 8 CAN junction connector
      *: w/ Dynamic Rear Steering System
      Result
      Result Proceed to
      OK A
      NG (No. 17 CAN junction connector CAN main wire) B
      NG (No. 8 CAN junction connector CAN main wire) C
      NG (Wire to ECU or sensor) D

    A

    REPLACE NO. 18 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 18 CAN JUNCTION CONNECTOR - NO. 17 CAN JUNCTION CONNECTOR)

    D

    GO TO STEP 18 Click here

    C

  8. CONNECT CONNECTOR


    1. Reconnect the b10 No. 18 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  9. CHECK FOR SHORT IN CAN BUS WIRES (NO. 8 CAN JUNCTION CONNECTOR)

    Tech Tips


    • Before disconnecting the connectors, make a note of where it is connected.

    • Reconnect the connector to its original position.


    1. Disconnect the No. 8 CAN junction connectors.

      B004CABC07
      *1 No. 8 CAN Junction Connector - -
      *a

      Rear view of wire harness connector

      (to No. 8 CAN Junction Connector)

      		 - -
      Wiring Color
      Code Color (CANH Side) Color (CANL Side) Connect to
      P125 Y W Skid control ECU assembly
      P126 B W Rack and pinion power steering gear assembly
      P127 P W Front steering control ECU*1
      P128 G W No. 18 CAN junction connector
      P130 BE W Driving support ECU assembly*2

      *1: w/ Variable Gear Ratio Steering System

      *2: w/ Pre-collision System

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      P125-1 (CANH) - P125-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Skid control ECU assembly
      P126-1 (CANH) - P126-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Rack and pinion power steering gear assembly
      P127-1 (CANH) - P127-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Front steering control ECU*1
      P128-1 (CANH) - P128-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 18 CAN junction connector
      P130-1 (CANH) - P130-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Driving support ECU assembly*2
      *1: w/ Variable Gear Ratio Steering System
      *2: w/ Pre-collision System
      Result
      Result Proceed to
      OK A
      NG (No. 18 CAN junction connector CAN main wire) B
      NG (Skid control ECU assembly CAN main wire) C
      NG (Wire to ECU or sensor) D

    A

    REPLACE NO. 8 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - NO. 18 CAN JUNCTION CONNECTOR)

    C

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - SKID CONTROL ECU ASSEMBLY)

    D

    GO TO STEP 18 Click here

  10. CONNECT CONNECTOR


    1. Reconnect the A9 skid control ECU assembly connector.

      Result
      Proceed to
      NEXT

    NEXT

  11. CHECK FOR SHORT IN CAN BUS WIRES (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 18 CAN JUNCTION CONNECTOR)


    1. B004BXLC16
      *a

      Front view of wire harness connector

      (to Central Gateway ECU [Network Gateway ECU])

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      P59-19 (CAYH) - P59-20 (CAYL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Result
      OK
      NG

    OK

    REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU) Click here

    NG

  12. CONNECT CONNECTOR


    1. Reconnect the P59 central gateway ECU (network gateway ECU) connector.

      Result
      Proceed to
      NEXT

    NEXT

  13. CHECK FOR SHORT IN CAN BUS WIRES (NO. 18 CAN JUNCTION CONNECTOR)


    1. B004CJAC21
      *a

      Front view of wire harness connector

      (to No. 18 CAN Junction Connector)
      *b to No. 17 CAN Junction Connector
      *c to Rear Steering Control ECU (w/ Dynamic Rear Steering System)
      *d to Central Gateway ECU (Network Gateway ECU)

      Disconnect the No. 18 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      b10-9 (CANH) - b10-20 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 17 CAN junction connector
      b10-10 (CANH) - b10-21 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Rear steering control ECU*
      b10-11 (CANH) - b10-22 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Central gateway ECU (network gateway ECU)
      *: w/ Dynamic Rear Steering System
      Result
      Result Proceed to
      OK A
      NG (Central gateway ECU [network gateway ECU] CAN main wire) B
      NG (No. 17 CAN junction connector CAN main wire) C
      NG (Wire to ECU or sensor) D

    A

    REPLACE NO. 18 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 18 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU])

    D

    GO TO STEP 18 Click here

    C

  14. CONNECT CONNECTOR


    1. Reconnect the b10 No. 18 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  15. CHECK FOR SHORT IN CAN BUS WIRES (NO. 17 CAN JUNCTION CONNECTOR)


    1. B004CJAC20
      *a

      Front view of wire harness connector

      (to No. 17 CAN Junction Connector)
      *b to No. 18 CAN Junction Connector
      *c to Absorber Control ECU
      *d to No. 8 CAN Junction Connector

      Disconnect the No. 17 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      X114-1 (CANH) - X114-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 18 CAN junction connector
      X114-2 (CANH) - X114-13 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Absorber control ECU
      X114-3 (CANH) - X114-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 8 CAN junction connector
      Result
      Result Proceed to
      OK A
      NG (No. 18 CAN junction connector CAN main wire) B
      NG (No. 8 CAN junction connector CAN main wire) C
      NG (Wire to ECU or sensor) D

    A

    REPLACE NO. 17 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 17 CAN JUNCTION CONNECTOR - NO. 18 CAN JUNCTION CONNECTOR)

    D

    GO TO STEP 18 Click here

    C

  16. CONNECT CONNECTOR


    1. Reconnect the X114 No. 17 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  17. CHECK FOR SHORT IN CAN BUS WIRES (NO. 8 CAN JUNCTION CONNECTOR)

    Tech Tips


    • Before disconnecting the connectors, make a note of where it is connected.

    • Reconnect the connector to its original position.


    1. Disconnect the No. 8 CAN junction connectors.

      B004CABC07
      *1 No. 8 CAN Junction Connector - -
      *a

      Rear view of wire harness connector

      (to No. 8 CAN Junction Connector)

      		 - -
      Wiring Color
      Code Color (CANH Side) Color (CANL Side) Connect to
      P125 Y W Skid control ECU assembly
      P126 B W Rack and pinion power steering gear assembly
      P127 P W Front steering control ECU*1
      P128 G W No. 17 CAN junction connector
      P130 BE W Driving support ECU assembly*2

      *1: w/ Variable Gear Ratio Steering System

      *2: w/ Pre-collision System

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      P125-1 (CANH) - P125-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Skid control ECU assembly
      P126-1 (CANH) - P126-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Rack and pinion power steering gear assembly
      P127-1 (CANH) - P127-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Front steering control ECU*1
      P128-1 (CANH) - P128-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 17 CAN junction connector
      P130-1 (CANH) - P130-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Driving support ECU assembly*2
      *1: w/ Variable Gear Ratio Steering System
      *2: w/ Pre-collision System
      Result
      Result Proceed to
      OK A
      NG (No. 17 CAN junction connector CAN main wire) B
      NG (Skid control ECU assembly CAN main wire) C
      NG (Wire to ECU or sensor) D

    A

    REPLACE NO. 8 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - NO. 17 CAN JUNCTION CONNECTOR)

    C

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - SKID CONTROL ECU ASSEMBLY)

    D

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


    1. B004B7WC10
      *a

      Component with harness connected

      (Central Gateway ECU [Network Gateway ECU])

      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.

      Click here

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      P59-19 (CAYH) - P59-20 (CAYL) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

      Tech Tips

      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.

      Result
      Result
      OK
      NG

    OK

    REPLACE ECU OR SENSOR

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR