CAN COMMUNICATION SYSTEM Short to GND in CAN Bus Line

DESCRIPTION

There may be a short circuit between the CAN bus lines and GND when the resistance between terminals 6 (CANH) and 4 (CG) or terminals 14 (CANL) and 4 (CG) of the DLC3 is below 200 Ω.

Symptom Trouble Area
The resistance between terminals 6 (CANH) and 4 (CG) or terminals 14 (CANL) and 4 (CG) of the DLC3 is below 200 Ω.

  • Short between CAN bus lines and GND

  • ECM

  • Air conditioning amplifier assembly*1

  • Certification ECU (smart key ECU assembly)*2

  • Headlight leveling ECU assembly*3

  • Combination meter assembly

  • CAN junction connector

WIRING DIAGRAM

A01BB1NE01

INSPECTION PROCEDURE

Note

For vehicles with a smart entry and start system:

Before replacing the certification ECU (smart key ECU assembly), refer to the smart entry and start system 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.

PROCEDURE


  1. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL


    1. Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.

      CAUTION:

      For vehicles with an airbag system:

      Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected Click here.


    NEXT

  2. CHECK FOR SHORT TO GND IN CAN BUS WIRE (DLC3 CAN BRANCH WIRE)


    1. A01BGEYE37
      Text in Illustration
      *a Front view of DLC3

      Disconnect the H64 CAN junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H23-6 (CANH) - H23-4 (CG) Ignition switch off 200 Ω or higher
      H23-14 (CANL) - H23-4 (CG) Ignition switch off 200 Ω or higher

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DLC3 (CANH, CANL)

    OK

  3. CHECK FOR SHORT TO GND IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - AIR CONDITIONING AMPLIFIER ASSEMBLY)

    Note

    For vehicles without an air conditioning system or with 5L-E engine type, go to "Check for Short to GND in CAN Bus Wire (CAN Junction Connector - Certification ECU)".


    1. A01BB7XE06
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN Junction Connector)
      *b Front view of DLC3

      Disconnect the CAN junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H62-1 (CANH) - H23-4 (CG) Ignition switch off 200 Ω or higher
      H62-2 (CANL) - H23-4 (CG) Ignition switch off 200 Ω or higher

    NG

    CONNECT CONNECTOR Click here

    OK

  4. CHECK FOR SHORT TO GND IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - CERTIFICATION ECU)

    Note

    For vehicles without a smart entry and start system, go to "Check for Short to GND in CAN Bus Wire (CAN Junction Connector - Headlight Leveling ECU Assembly)".


    1. A01BB7XE07
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN Junction Connector)
      *b Front view of DLC3

      Disconnect the CAN junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H66-1 (CANH) - H23-4 (CG) Ignition switch off 200 Ω or higher
      H66-2 (CANL) - H23-4 (CG) Ignition switch off 200 Ω or higher

    NG

    CONNECT CONNECTOR Click here

    OK

  5. CHECK FOR SHORT TO GND IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - HEADLIGHT LEVELING ECU ASSEMBLY)

    Note

    For vehicles with a halogen headlight, go to "Check for Short to GND in CAN Bus Wire (CAN Junction Connector - ECM)".


    1. A01BB7XE08
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN Junction Connector)
      *b Front view of DLC3

      Disconnect the CAN junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H90-1 (CANH) - H23-4 (CG) Ignition switch off 200 Ω or higher
      H90-2 (CANL) - H23-4 (CG) Ignition switch off 200 Ω or higher

    NG

    CONNECT CONNECTOR Click here

    OK

  6. CHECK FOR SHORT TO GND IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - ECM)


    1. A01BB7XE09
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN Junction Connector)
      *b Front view of DLC3

      Disconnect the CAN junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H63-1 (CANH) - H23-4 (CG) Ignition switch off 200 Ω or higher
      H63-2 (CANL) - H23-4 (CG) Ignition switch off 200 Ω or higher

    NG

    CONNECT CONNECTOR Click here

    OK

  7. CHECK FOR SHORT TO GND IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - COMBINATION METER ASSEMBLY)


    1. A01BB7XE10
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN Junction Connector)
      *b Front view of DLC3

      Disconnect the CAN junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H65-1 (CANH) - H23-4 (CG) Ignition switch off 200 Ω or higher
      H65-2 (CANL) - H23-4 (CG) Ignition switch off 200 Ω or higher

    NG

    CONNECT CONNECTOR Click here

    OK

    REPLACE CAN JUNCTION CONNECTOR

  8. CONNECT CONNECTOR


    1. Reconnect all wire harness CAN junction connectors.


    NEXT

  9. CHECK FOR SHORT TO GND IN CAN BUS WIRE (AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. A01BFO6E05
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Air Conditioning Amplifier Assembly)
      *b Front view of DLC3

      Disconnect the air conditioning amplifier assembly connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H18-10 (CANH) - H23-4 (CG) Ignition switch off 200 Ω or higher
      H18-11 (CANL) - H23-4 (CG) Ignition switch off 200 Ω or higher

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO AIR CONDITIONING AMPLIFIER ASSEMBLY (CANH, CANL)

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

  10. CONNECT CONNECTOR


    1. Reconnect all wire harness CAN junction connectors.


    NEXT

  11. CHECK FOR SHORT TO GND IN CAN BUS WIRE (CERTIFICATION ECU)


    1. A01BEJZE03
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Certification ECU [Smart Key ECU Assembly])
      *b Front view of DLC3

      Disconnect the certification ECU (smart key ECU assembly) connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      B76-40 (CANH) - H23-4 (CG) Ignition switch off 200 Ω or higher
      B76-18 (CANL) - H23-4 (CG) Ignition switch off 200 Ω or higher

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO CERTIFICATION ECU (CANH, CANL)

    OK

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

  12. CONNECT CONNECTOR


    1. Reconnect all wire harness CAN junction connectors.


    NEXT

  13. CHECK FOR SHORT TO GND IN CAN BUS WIRE (HEADLIGHT LEVELING ECU ASSEMBLY)


    1. A01BHJ8E13
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Headlight Leveling ECU Assembly)
      *b Front view of DLC3

      Disconnect the headlight leveling ECU assembly connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A39-6 (CANH) - H23-4 (CG) Ignition switch off 200 Ω or higher
      A39-7 (CANL) - H23-4 (CG) Ignition switch off 200 Ω or higher
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    B

    REPLACE HEADLIGHT LEVELING ECU ASSEMBLY Click here

    C

    REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO HEADLIGHT LEVELING ECU ASSEMBLY (CANH, CANL)

    A

    REPLACE HEADLIGHT LEVELING ECU ASSEMBLY Click here

  14. CONNECT CONNECTOR


    1. Reconnect all wire harness CAN junction connectors.


    NEXT

  15. CHECK FOR SHORT TO GND IN CAN BUS WIRE (ECM)


    1. Disconnect the ECM connector.

      A01BC68E02
      Text in Illustration
      *A for 1KD-FTV (w/ DPF) *B for 1KD-FTV (w/o DPF)
      *C for 2KD-FTV *D for 1TR-FE, 2TR-FE
      *E for 5L-E - -
      *a

      Front view of wire harness connector

      (to ECM)

      		 *b Front view of DLC3

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

      Standard Resistance
      for 1KD-FTV (w/ DPF)
      Tester Connection Switch Condition Specified Condition
      B73-7 (CANH) - H23-4 (CG) Ignition switch off 200 Ω or higher
      B73-6 (CANL) - H23-4 (CG) Ignition switch off 200 Ω or higher
      for 1KD-FTV (w/o DPF)
      Tester Connection Switch Condition Specified Condition
      B72-7 (CANH) - H23-4 (CG) Ignition switch off 200 Ω or higher
      B72-6 (CANL) - H23-4 (CG) Ignition switch off 200 Ω or higher
      for 2KD-FTV
      Tester Connection Switch Condition Specified Condition
      B88-6 (CANH) - H23-4 (CG) Ignition switch off 200 Ω or higher
      B88-7 (CANL) - H23-4 (CG) Ignition switch off 200 Ω or higher
      for 1TR-FE, 2TR-FE
      Tester Connection Switch Condition Specified Condition
      B71-8 (CANH) - H23-4 (CG) Ignition switch off 200 Ω or higher
      B71-9 (CANL) - H23-4 (CG) Ignition switch off 200 Ω or higher
      for 5L-E
      Tester Connection Switch Condition Specified Condition
      B74-10 (CANH) - H23-4 (CG) Ignition switch off 200 Ω or higher
      B74-11 (CANL) - H23-4 (CG) Ignition switch off 200 Ω or higher

      Tech Tips

      *: Replacement procedure:



    NG

    REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO ECM (CANH, CANL)

    OK

    REPLACE ECM*

  16. CONNECT CONNECTOR


    1. Reconnect all wire harness CAN junction connectors.


    NEXT

  17. CHECK FOR SHORT TO GND IN CAN BUS WIRE (COMBINATION METER ASSEMBLY)


    1. A01BFO6E06
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Combination Meter Assembly)
      *b Front view of DLC3

      Disconnect the combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H20-23 (CANH) - H23-4 (CG) Ignition switch off 200 Ω or higher
      H20-22 (CANL) - H23-4 (CG) Ignition switch off 200 Ω or higher

    NG

    REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO COMBINATION METER ASSEMBLY (CANH, CANL)

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here