CAN COMMUNICATION SYSTEM Check Bus 4 Line for Short to GND

DESCRIPTION

There may be a short circuit between one of the CAN bus lines and GND when there is no resistance between terminal 22 (CA2H) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3, or terminal 7 (CA2L) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3.

Symptom Trouble Area
There is no resistance between terminal 22 (CA2H) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3, or terminal 7 (CA2L) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3.

  • Short to ground in CAN main bus wire

  • Short to ground in CAN branch wire

  • Central gateway ECU (network gateway ECU)

  • Skid control ECU assembly

  • Parking brake ECU assembly

  • Rear steering control ECU*1

  • Rack and pinion power steering gear assembly

  • ECM

  • Pedestrian detection ECU assembly

  • Front Steering Control ECU*2

  • Hybrid vehicle control ECU assembly

  • Yaw rate sensor

  • Airbag ECU assembly

  • Steering sensor

  • Absorber control ECU

  • Tire pressure warning ECU and receiver

  • No. 1 CAN junction terminal

  • No. 2 CAN junction terminal

  • No. 2 CAN junction connector

  • No. 12 CAN junction connector

  • No. 13 CAN junction connector
*1: w/ Dynamic Rear Steering System
*2: w/ Variable Gear Ratio Steering System

WIRING DIAGRAM

B004BT4E02
B004BBRE02
B004ASME03

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 VEHICLE TYPE


    1. Check vehicle type.

      Result
      Result Proceed to
      for LHD A
      for RHD B

    B

    CHECK FOR SHORT TO GND IN CAN BUS WIRE (NO. 12 CAN JUNCTION CONNECTOR) Click here

    A

  2. CHECK FOR SHORT TO GND IN CAN BUS WIRE (NO. 12 CAN JUNCTION CONNECTOR)


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

    2. B004CV0C04
      *a

      Front view of wire harness connector

      (to No. 12 CAN Junction Connector)
      *b Front view of DLC3
      *c to No. 1 CAN Junction Terminal
      *d to Tire Pressure Warning ECU and Receiver
      *e to Absorber Control ECU
      *f to No. 2 CAN Junction Connector
      *g to Central Gateway ECU (Network Gateway ECU)

      Disconnect the No. 12 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
      X96-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher No. 1 CAN junction terminal
      X96-7 (CANL) - P12-4 (CG)
      X96-2 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Tire pressure warning ECU and receiver
      X96-8 (CANL) - P12-4 (CG)
      X96-3 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Absorber control ECU
      X96-9 (CANL) - P12-4 (CG)
      X96-4 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher No. 2 CAN junction connector
      X96-10 (CANL) - P12-4 (CG)
      X96-5 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Central gateway ECU (network gateway ECU)
      X96-11 (CANL) - P12-4 (CG)
      Result
      Result Proceed to
      OK A
      NG (No. 2 CAN junction connector CAN main wire) B
      NG (Central gateway ECU [network gateway ECU] CAN branch wire) C
      NG (ECU or sensor branch wire) D

    A

    REPLACE NO. 12 CAN JUNCTION CONNECTOR

    C

    CONNECT CONNECTOR Click here

    D

    GO TO STEP 16 Click here

    B

  3. CONNECT CONNECTOR


    1. Reconnect the X96 No. 12 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

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


    1. Disconnect the No. 2 CAN junction connector.

      B004ARNC04
      *a

      Front view of wire harness connector

      (to No. 2 CAN Junction Connector)

      		 *b Front view of DLC3
      *c to Pedestrian Detection ECU Assembly *d to Front Steering Control ECU (w/ Variable Gear Ratio Steering System)
      *e to Hybrid Vehicle Control ECU Assembly *f to Yaw Rate Sensor
      *g to Airbag ECU Assembly *h to Steering Sensor
      *i to No. 13 CAN Junction Connector *j to No. 12 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
      P108-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Pedestrian detection ECU assembly
      P108-12 (CANL) - P12-4 (CG)
      P108-2 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Front steering control ECU*
      P108-13 (CANL) - P12-4 (CG)
      P108-3 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Hybrid vehicle control ECU assembly
      P108-14 (CANL) - P12-4 (CG)
      P108-4 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Yaw rate sensor
      P108-15 (CANL) - P12-4 (CG)
      P108-5 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Airbag ECU assembly
      P108-16 (CANL) - P12-4 (CG)
      P108-6 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Steering sensor
      P108-17 (CANL) - P12-4 (CG)
      P108-7 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher No. 13 CAN junction connector
      P108-18 (CANL) - P12-4 (CG)
      P108-8 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher No. 12 CAN junction connector
      P108-19 (CANL) - P12-4 (CG)
      *: w/ Variable Gear Ratio Steering System
      Result
      Result Proceed to
      OK A
      NG (No. 12 CAN junction connector CAN main wire) B
      NG (No. 13 CAN junction connector CAN main wire) C
      NG (Wire to ECU or sensor) D

    A

    REPLACE NO. 2 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 2 CAN JUNCTION CONNECTOR - NO. 12 CAN JUNCTION CONNECTOR)

    C

    CONNECT CONNECTOR Click here

    D

    GO TO STEP 16 Click here

  5. CONNECT CONNECTOR


    1. Reconnect the X96 No. 12 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  6. CHECK FOR SHORT TO GND IN CAN BUS WIRE (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 12 CAN JUNCTION CONNECTOR)


    1. B004CLAC57
      *a

      Front view of wire harness connector

      (to Central Gateway ECU [Network Gateway ECU])
      *b Front view of DLC3

      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
      P59-22 (CA2H) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      P59-7 (CA2L) - P12-4 (CG)
      Result
      Result
      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. 12 CAN JUNCTION CONNECTOR)

  7. CONNECT CONNECTOR


    1. Reconnect the P108 No. 2 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  8. CHECK FOR SHORT TO GND IN CAN BUS WIRE (NO. 13 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. 13 CAN junction connectors.

      B004BXCC04
      *1 No. 13 CAN Junction Connector - -
      *a

      Rear view of wire harness connector

      (to No. 13 CAN Junction Connector)

      		 *b Front view of DLC3
      Wiring Color
      Code Color (CANH Side) Color (CANL Side) Connect to
      X100 V P Parking brake ECU assembly
      X101 LG P Rear steering control ECU*
      X102 B P Rack and pinion power steering gear assembly
      X103 GR P No. 2 CAN junction connector
      X104 G P Skid control ECU assembly
      X106 BE P ECM
      X107 R P No. 2 CAN junction terminal

      *: w/ Dynamic Rear Steering System

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      X100-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Parking brake ECU assembly
      X100-2 (CANL) - P12-4 (CG)
      X101-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Rear steering control ECU*
      X101-2 (CANL) - P12-4 (CG)
      X102-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Rack and pinion power steering gear assembly
      X102-2 (CANL) - P12-4 (CG)
      X103-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher No. 2 CAN junction connector
      X103-2 (CANL) - P12-4 (CG)
      X104-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Skid control ECU assembly
      X104-2 (CANL) - P12-4 (CG)
      X106-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher ECM
      X106-2 (CANL) - P12-4 (CG)
      X107-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher No. 2 CAN junction terminal
      X107-2 (CANL) - P12-4 (CG)
      *: w/ Dynamic Rear Steering System
      Result
      Result Proceed to
      OK A
      NG (No. 2 CAN junction connector CAN main wire) B
      NG (Wire to ECU or sensor) C

    A

    REPLACE NO. 13 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 13 CAN JUNCTION CONNECTOR - NO. 2 CAN JUNCTION CONNECTOR)

    C

    GO TO STEP 16 Click here

  9. CHECK FOR SHORT TO GND IN CAN BUS WIRE (NO. 12 CAN JUNCTION CONNECTOR)


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

    2. B004CV0C06
      *a

      Front view of wire harness connector

      (to No. 12 CAN Junction Connector)
      *b Front view of DLC3
      *c to No. 1 CAN Junction Terminal
      *d to Tire Pressure Warning ECU and Receiver
      *e to Absorber Control ECU
      *f to No. 2 CAN Junction Connector
      *g to Skid Control ECU Assembly

      Disconnect the No. 12 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
      X96-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher No. 1 CAN junction terminal
      X96-7 (CANL) - P12-4 (CG)
      X96-2 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Tire pressure warning ECU and receiver
      X96-8 (CANL) - P12-4 (CG)
      X96-3 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Absorber control ECU
      X96-9 (CANL) - P12-4 (CG)
      X96-4 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher No. 2 CAN junction connector
      X96-10 (CANL) - P12-4 (CG)
      X96-6 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Skid control ECU assembly
      X96-12 (CANL) - P12-4 (CG)
      Result
      Result Proceed to
      OK A
      NG (No. 2 CAN junction connector CAN main wire) B
      NG (ECU or sensor branch wire) C

    A

    REPLACE NO. 12 CAN JUNCTION CONNECTOR

    C

    GO TO STEP 16 Click here

    B

  10. CONNECT CONNECTOR


    1. Reconnect the X96 No. 12 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

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


    1. Disconnect the No. 2 CAN junction connector.

      B004ARNC04
      *a

      Front view of wire harness connector

      (to No. 2 CAN Junction Connector)

      		 *b Front view of DLC3
      *c to Pedestrian Detection ECU Assembly *d to Front Steering Control ECU (w/ Variable Gear Ratio Steering System)
      *e to Hybrid Vehicle Control ECU Assembly *f to Yaw Rate Sensor
      *g to Airbag ECU Assembly *h to Steering Sensor
      *i to No. 13 CAN Junction Connector *j to No. 12 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
      P108-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Pedestrian detection ECU assembly
      P108-12 (CANL) - P12-4 (CG)
      P108-2 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Front steering control ECU*
      P108-13 (CANL) - P12-4 (CG)
      P108-3 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Hybrid vehicle control ECU assembly
      P108-14 (CANL) - P12-4 (CG)
      P108-4 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Yaw rate sensor
      P108-15 (CANL) - P12-4 (CG)
      P108-5 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Airbag ECU assembly
      P108-16 (CANL) - P12-4 (CG)
      P108-6 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Steering sensor
      P108-17 (CANL) - P12-4 (CG)
      P108-7 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher No. 13 CAN junction connector
      P108-18 (CANL) - P12-4 (CG)
      P108-8 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher No. 12 CAN junction connector
      P108-19 (CANL) - P12-4 (CG)
      *: w/ Variable Gear Ratio Steering System
      Result
      Result Proceed to
      OK A
      NG (No. 12 CAN junction connector CAN main wire) B
      NG (No. 13 CAN junction connector CAN main wire) C
      NG (Wire to ECU or sensor) D

    A

    REPLACE NO. 2 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 2 CAN JUNCTION CONNECTOR - NO. 12 CAN JUNCTION CONNECTOR)

    D

    GO TO STEP 16 Click here

    C

  12. CONNECT CONNECTOR


    1. Reconnect the P108 No. 2 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  13. CHECK FOR SHORT TO GND IN CAN BUS WIRE (NO. 13 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. 13 CAN junction connectors.

      B004BXCC06
      *1 No. 13 CAN Junction Connector - -
      *a

      Rear view of wire harness connector

      (to No. 13 CAN Junction Connector)

      		 *b Front view of DLC3
      Wiring Color
      Code Color (CANH Side) Color (CANL Side) Connect to
      X100 V P Parking brake ECU assembly
      X101 LG P Rear steering control ECU*
      X102 B P Rack and pinion power steering gear assembly
      X103 GR P No. 2 CAN junction connector
      X105 L P Central gateway ECU (network gateway ECU)
      X106 BE P ECM
      X107 R P No. 2 CAN junction terminal

      *: w/ Dynamic Rear Steering System

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      X100-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Parking brake ECU assembly
      X100-2 (CANL) - P12-4 (CG)
      X101-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Rear steering control ECU*
      X101-2 (CANL) - P12-4 (CG)
      X102-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Rack and pinion power steering gear assembly
      X102-2 (CANL) - P12-4 (CG)
      X103-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher No. 2 CAN junction connector
      X103-2 (CANL) - P12-4 (CG)
      X105-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Central gateway ECU (network gateway ECU)
      X105-2 (CANL) - P12-4 (CG)
      X106-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher ECM
      X106-2 (CANL) - P12-4 (CG)
      X107-1 (CANH) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher No. 2 CAN junction terminal
      X107-2 (CANL) - P12-4 (CG)
      *: w/ Dynamic Rear Steering System
      Result
      Result Proceed to
      OK A
      NG (No. 2 CAN junction connector CAN main wire) B
      NG (Central gateway ECU [network gateway ECU] CAN branch wire) C
      NG (Wire to ECU or sensor) D

    A

    REPLACE NO. 13 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 13 CAN JUNCTION CONNECTOR - NO. 2 CAN JUNCTION CONNECTOR)

    D

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

    C

  14. CONNECT CONNECTOR


    1. Reconnect the No. 13 CAN junction connectors.

      Result
      Proceed to
      NEXT

    NEXT

  15. CHECK FOR SHORT TO GND IN CAN BUS WIRE (CENTRAL GATEWAY ECU [NETWORK GATEWAY ECU] - NO. 13 CAN JUNCTION CONNECTOR)


    1. B004CLAC57
      *a

      Front view of wire harness connector

      (to Central Gateway ECU [Network Gateway ECU])
      *b Front view of DLC3

      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
      P59-22 (CA2H) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      P59-7 (CA2L) - P12-4 (CG)
      Result
      Result
      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. 13 CAN JUNCTION CONNECTOR)

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


    1. B004B0UC12
      *a

      Component with harness connected

      (Central Gateway ECU [Network Gateway ECU])
      *b Front view of DLC3

      Reconnect all wire harness connectors.

    2. 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
      P59-22 (CA2H) - P12-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      P59-7 (CA2L) - P12-4 (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
      Result
      OK
      NG

    OK

    REPLACE ECU OR SENSOR

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR