CAN COMMUNICATION SYSTEM Check CAN Bus Lines for Short Circuit (RHD Models)

DESCRIPTION

There may be a short circuit in the CAN main wire and/or CAN branch wire when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is below 54 Ω.

Symptom Trouble Area
Resistance between terminals 6 (CANH) and 14 (CANL) of DLC3 is below 54 Ω.

  • Short in CAN bus wire

  • Skid control ECU

  • Power steering ECU

  • Steering angle sensor

  • Yaw rate sensor

  • ECM

  • Center airbag sensor assembly

  • Air conditioning amplifier

  • Combination meter

  • Main body ECU

  • CAN junction connector CTR

  • CAN junction connector RH

WIRING DIAGRAM

A017GBSE02
A017CQGE01

INSPECTION PROCEDURE

Note


  • Turn the ignition switch off before measuring the resistances of CAN bus main wires and CAN bus branch wires.

  • After the ignition switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.

  • Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches, or the doors. If any doors need to be opened in order to check the connectors, open the doors and leave them open.

Tech Tips


  • Operating the ignition switch, any other switches, or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.

  • Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below will help determine the cause of the malfunction.

PROCEDURE


  1. CHECK FOR SHORT IN CAN BUS WIRES (CAN JUNCTION CONNECTOR CTR)


    1. Turn the ignition switch off.

    2. Disconnect the CAN junction connector CTR.

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

      A017G9DE11
      Standard resistance
      Tester Connection Wiring Color Connect to Condition Specified Condition
      D47-1 (CANH) - D47-12 (CANL) SB - W CAN junction connector RH Ignition switch off 108 to 132 Ω
      D47-4 (CANH) - D47-15 (CANL) L - W DLC3 Ignition switch off 1 MΩ or higher
      D47-5 (CANH) - D47-16 (CANL) R - W ECM Ignition switch off 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (DLC3 branch wire) B
      NG (ECM main wire) C
      NG (CAN junction connector RH main wire) D

    B

    REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DLC3

    C

    CHECK FOR SHORT IN CAN BUS WIRES (ECM MAIN WIRE) Click here

    D

    CHECK FOR SHORT IN CAN BUS WIRES (CAN JUNCTION CONNECTOR RH) Click here

    A

  2. CHECK FOR SHORT IN CAN BUS WIRES (CAN JUNCTION CONNECTOR CTR)


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

      A017G9DE12
      Standard resistance
      Tester Connection Wiring Color Connect to Condition Specified Condition
      D47-2 (CANH) - D47-13 (CANL) V - W Yaw rate sensor Ignition switch off 1 MΩ or higher
      D47-3 (CANH) - D47-14 (CANL) Y - W Center airbag sensor assembly Ignition switch off 1 MΩ or higher
      D47-6 (CANH) - D47-17 (CANL) P - W Air conditioning amplifier Ignition switch off 1 MΩ or higher
      D47-8 (CANH) - D47-19 (CANL) GR - W Main body ECU Ignition switch off 1 MΩ or higher
      Result
      Result Proceed to
      OK A
      NG (Yaw rate sensor branch wire) B
      NG (Center airbag sensor assembly branch wire) C
      NG (Air conditioning amplifier branch wire) D
      NG (Main body ECU branch wire) E

    B

    CHECK FOR SHORT IN CAN BUS WIRES (YAW RATE SENSOR BRANCH WIRE) Click here

    C

    CHECK FOR SHORT IN CAN BUS WIRES (CENTER AIRBAG SENSOR ASSEMBLY BRANCH WIRE) Click here

    D

    CHECK FOR SHORT IN CAN BUS WIRES (AIR CONDITIONING AMPLIFIER BRANCH WIRE) Click here

    E

    CHECK FOR SHORT IN CAN BUS WIRES (MAIN BODY ECU BRANCH WIRE) Click here

    A

    REPLACE CAN JUNCTION CONNECTOR CTR

  3. CHECK FOR SHORT IN CAN BUS WIRES (ECM MAIN WIRE)


    1. A017EELE04

      Disconnect the ECM connector.

    2. A017BH4E70

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D47-5 (CANH) - D47-16 (CANL) Ignition switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (ECM MAIN WIRE)

    OK

    REPLACE ECM Click here

  4. CHECK FOR SHORT IN CAN BUS WIRES (CAN JUNCTION CONNECTOR RH)


    1. Disconnect the CAN junction connector RH.

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

      A017G9DE13

      Tech Tips

      The resistance must be measured after the CAN junction connector CTR is disconnected.

      Standard resistance
      Tester Connection Wiring Color Connect to Condition Specified Condition
      D51-3 (CANH) - D51-14 (CANL) P - W Combination meter Ignition switch off 108 to 132 Ω
      D51-5 (CANH) - D51-16 (CANL) SB - W CAN junction connector CTR Ignition switch off 1 MΩ or higher
      Result
      Result Proceed to
      OK A
      NG (Combination meter main wire) B
      NG (CAN junction connector main wire) C

    B

    CHECK FOR SHORT IN CAN BUS WIRES (COMBINATION METER ECU MAIN WIRE) Click here

    C

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (CAN JUNCTION CONNECTOR CTR - CAN JUNCTION CONNECTOR RH)

    A

  5. CHECK FOR SHORT IN CAN BUS WIRES (CAN JUNCTION CONNECTOR RH)


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

      A017G9DE14
      Standard resistance
      Tester Connection Wiring Color Connect to Condition Specified Condition
      D51-1 (CANH) - D51-12 (CANL) R - W Steering angle sensor Ignition switch off 1 MΩ or higher
      D51-2 (CANH) - D51-13 (CANL) BR - W Power steering ECU Ignition switch off 1 MΩ or higher
      D51-4 (CANH) - D51-15 (CANL) B - W Skid control ECU Ignition switch off 1 MΩ or higher
      Result
      Result Proceed to
      OK A
      NG (Steering angle sensor branch wire) B
      NG (Power steering ECU) C
      NG (Skid control ECU branch wire) D

    B

    CHECK FOR SHORT IN CAN BUS WIRES (STEERING ANGLE SENSOR BRANCH WIRE) Click here

    C

    CHECK FOR SHORT IN CAN BUS WIRES (POWER STEERING ECU BRANCH WIRE) Click here

    D

    CHECK FOR SHORT IN CAN BUS WIRES (SKID CONTROL ECU BRANCH WIRE) Click here

    A

    REPLACE CAN JUNCTION CONNECTOR RH

  6. CHECK FOR SHORT IN CAN BUS WIRES (COMBINATION METER ECU MAIN WIRE)


    1. A017BD2E21

      Disconnect the combination meter connector.

    2. A017BH4E73

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D51-3 (CANH) - D51-14 (CANL) Ignition switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (COMBINATION METER ECU MAIN WIRE)

    OK

    REPLACE COMBINATION METER Click here

  7. CHECK FOR SHORT IN CAN BUS WIRES (YAW RATE SENSOR BRANCH WIRE)


    1. A017DEAE04

      Disconnect the yaw rate sensor connector.

    2. A017BH4E68

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D47-2 (CANH) - D47-13 (CANL) Ignition switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (YAW RATE SENSOR BRANCH WIRE)

    OK

    REPLACE YAW RATE SENSOR Click here

  8. CHECK FOR SHORT IN CAN BUS WIRES (CENTER AIRBAG SENSOR ASSEMBLY BRANCH WIRE)


    1. A017DMZE22

      Disconnect the center airbag sensor assembly connector.

    2. A017BH4E69

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D47-3 (CANH) - D47-14 (CANL) Ignition switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CENTER AIRBAG SENSOR ASSEMBLY)

    OK

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here

  9. CHECK FOR SHORT IN CAN BUS WIRES (AIR CONDITIONING AMPLIFIER BRANCH WIRE)


    1. A017FS6E06

      Disconnect the air conditioning amplifier connector.

    2. A017BH4E65

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D47-6 (CANH) - D47-17 (CANL) Ignition switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (AIR CONDITIONING AMPLIFIER BRANCH WIRE)

    OK

    REPLACE AIR CONDITIONING AMPLIFIER Click here

  10. CHECK FOR SHORT IN CAN BUS WIRES (MAIN BODY ECU BRANCH WIRE)


    1. A017F33E05

      Disconnect the main body ECU connector.

    2. A017BH4E72

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D47-8 (CANH) - D47-19 (CANL) Ignition switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (MAIN BODY ECU BRANCH WIRE)

    OK

    REPLACE MAIN BODY ECU

  11. CHECK FOR SHORT IN CAN BUS WIRES (STEERING ANGLE SENSOR BRANCH WIRE)


    1. A017FNVE03

      Disconnect the steering angle sensor connector.

    2. A017BH4E67

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D51-1 (CANH) - D51-12 (CANL) Ignition switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (STEERING ANGLE SENSOR BRANCH WIRE)

    OK

    REPLACE STEERING ANGLE SENSOR Click here

  12. CHECK FOR SHORT IN CAN BUS WIRES (POWER STEERING ECU BRANCH WIRE)


    1. A017BE3E11

      Disconnect the power steering ECU connector.

    2. A017BH4E77

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D51-2 (CANH) - D51-13 (CANL) Ignition switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (POWER STEERING ECU BRANCH WIRE)

    OK

    REPLACE POWER STEERING ECU Click here

  13. CHECK FOR SHORT IN CAN BUS WIRES (SKID CONTROL ECU BRANCH WIRE)


    1. A017C50E48

      Disconnect the skid control ECU connector.

    2. A017BH4E74

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D51-4 (CANH) - D51-15 (CANL) Ignition switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (SKID CONTROL ECU BRANCH WIRE)

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU BRANCH WIRE) Click here