CAN COMMUNICATION SYSTEM Check Chassis Local Bus Line for Short to GND

DESCRIPTION

There may be a short circuit between one of the CAN bus lines and +B when there is no resistance between terminal 3 (CANP) of the No. 8 CAN junction terminal and terminal 4 (CG) of the DLC3, or terminal 2 (CANN) of the No. 8 CAN junction terminal and terminal 4 (CG) of the DLC3.

Symptom Trouble Area
There is no resistance between terminal 3 (CANP) of the No. 8 CAN junction terminal and terminal 4 (CG) of the DLC3, or terminal 2 (CANN) of the No. 8 CAN junction terminal and terminal 4 (CG) of the DLC3.

  • Short to GND in CAN main bus wire

  • Short to GND in CAN branch wire

  • Driving support ECU assembly*1

  • Brake actuator assembly (skid control ECU)

  • Rack and pinion power steering gear assembly

  • Front steering control ECU*2

  • Suspension control ECU*3

  • Rear steering control ECU*4

  • Absorber control ECU*5

  • No. 8 CAN junction terminal

  • No. 10 CAN junction terminal

  • No. 5 CAN junction connector

  • No. 15 CAN junction connector
*1: w/ Pre-collision system
*2: w/ Variable Gear Ratio Steering System
*3: w/ Air Suspension System
*4: w/ Dynamic Rear Steering System
*5: w/ Adaptive Variable Suspension System

WIRING DIAGRAM

B006BVRE01

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 engine 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 (-) 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 negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) 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 engine 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 TO GND IN CAN BUS WIRE (NO. 5 CAN JUNCTION CONNECTOR)


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

    2. Disconnect the G123 No. 5 CAN junction connector.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition Connected to
      G123-11 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher No. 15 CAN junction connector
      G123-1 (CANL) - G20-4 (CG)
      G123-12 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Rack and pinion power steering gear assembly
      G123-2 (CANL) - G20-4 (CG)
      G123-13 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Driving support ECU assembly*1
      G123-3 (CANL) - G20-4 (CG)
      G123-15 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Brake actuator assembly (skid control ECU)
      G123-5 (CANL) - G20-4 (CG)
      G123-16 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Front steering control ECU*2
      G123-6 (CANL) - G20-4 (CG)
      G123-18 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher No. 10 CAN junction terminal
      G123-8 (CANL) - G20-4 (CG)
      *1: w/ Pre-collision System
      *2: w/ Variable Gear Ratio Steering System
      for RHD
      Tester Connection Condition Specified Condition Connected to
      G123-11 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher No. 10 CAN junction terminal
      G123-1 (CANL) - G20-4 (CG)
      G123-12 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Front steering control ECU*2
      G123-2 (CANL) - G20-4 (CG)
      G123-13 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Driving support ECU assembly*1
      G123-3 (CANL) - G20-4 (CG)
      G123-14 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Rack and pinion power steering gear assembly
      G123-4 (CANL) - G20-4 (CG)
      G123-17 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher No. 15 CAN junction connector
      G123-7 (CANL) - G20-4 (CG)
      G123-18 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Brake actuator assembly (skid control ECU)
      G123-8 (CANL) - G20-4 (CG)
      *1: w/ Pre-collision System
      *2: w/ Variable Gear Ratio Steering System
      Result
      Result Proceed to
      OK A
      NG (No. 15 CAN junction connector CAN main wire) B
      NG (Wire to ECU or sensor) C

    A

    REPLACE NO. 16 CAN JUNCTION CONNECTOR

    C

    GO TO STEP 4 Click here

    B

  2. CHECK FOR SHORT TO GND IN CAN BUS WIRE (NO. 15 CAN JUNCTION CONNECTOR)


    1. Reconnect the G123 No. 5 CAN junction connector.

    2. Disconnect the L120 No. 15 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
      L120-1 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Suspension control ECU*1
      L120-7 (CANL) - G20-4 (CG)
      L120-2 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Absorber control ECU*2
      L120-8 (CANL) - G20-4 (CG)
      L120-3 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher No. 8 CAN junction terminal
      L120-9 (CANL) - G20-4 (CG)
      L120-4 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher No. 5 CAN junction connector
      L120-10 (CANL) - G20-4 (CG)
      L120-5 (CANH) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Rear steering control ECU*3
      L120-11 (CANL) - G20-4 (CG)
      *1: w/ Air Suspension System
      *2: w/ Adaptive Variable Suspension System
      *3: w/ Dynamic Rear Steering System
      Result
      Result Proceed to
      OK A
      NG (No. 8 CAN junction terminal CAN main wire) B
      NG (No. 5 CAN junction connector CAN main wire) C
      NG (Wire to ECU or sensor) D

    A

    REPLACE NO. 15 CAN JUNCTION CONNECTOR

    C

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 15 CAN JUNCTION CONNECTOR - NO. 5 CAN JUNCTION CONNECTOR)

    D

    CHECK FOR SHORT TO GND IN CAN BUS WIRE (ECU, SENSOR) Click here

    B

  3. CHECK FOR SHORT TO GND IN CAN BUS WIRE (NO. 8 CAN JUNCTION TERMINAL - NO. 15 CAN JUNCTION CONNECTOR)


    1. Reconnect the L120 No. 15 CAN junction connector.

    2. Disconnect the L133 No. 8 CAN junction terminal connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L133-3 (CANP) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      L133-2 (CANN) - G20-4 (CG)
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NO. 8 CAN JUNCTION TERMINAL

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 8 CAN JUNCTION TERMINAL - NO. 15 CAN JUNCTION CONNECTOR)

  4. CHECK FOR SHORT TO GND IN CAN BUS WIRE (ECU, SENSOR)


    1. Reconnect all wire harness connectors.

    2. B006DWQC88
      *a

      Component with harness connected

      (No. 8 CAN Junction Terminal)

      Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the bus wire shorted to GND is connected.

      Click here

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L133-3 (CANP) - G20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      L133-2 (CANN) - G20-4 (CG)

      Tech Tips


      • If the resistance changes to 200 Ω or higher 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 to ground 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