CAN COMMUNICATION SYSTEM Check CAN Bus Line for Short to +B (RHD Models)

DESCRIPTION

There may be a short circuit between the CAN bus line and +B when no resistance exists between terminals 6 (CANH) and 16 (BAT) or terminals 14 (CANL) and 16 (BAT) of the DLC3.

Symptom Trouble Area
No resistance exists between terminals 6 (CANH) and 16 (BAT) or terminals 14 (CANL) and 16 (BAT) of the DLC3.

  • Short to +B 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 ECU

  • Main body ECU

  • CAN junction connector CTR

  • CAN junction connector RH

WIRING DIAGRAM

A017GBSE03
A017CQGE02

INSPECTION PROCEDURE

Note


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

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

  • 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 the 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 TO B+ IN CAN BUS WIRE (CAN JUNCTION CONNECTOR CTR)


    1. Turn the ignition switch off, and disconnect negative battery terminal.

    2. Disconnect the CAN junction connector CTR.

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

      A017BAHE23
      Standard resistance
      Tester Connection Wiring Color Connected to Condition Specified Condition
      D47-1 (CANH) - D43-16 (BAT) SB - LG CAN junction connector RH Disconnect negative battery terminal 6 kΩ or higher
      D47-12 (CANL) - D43-16 (BAT) W - LG CAN junction connector RH Disconnect negative battery terminal 6 kΩ or higher
      D47-4 (CANH) - D43-16 (BAT) L - LG DLC3 Disconnect negative battery terminal 6 kΩ or higher
      D47-15 (CANL) - D43-16 (BAT) W - LG DLC3 Disconnect negative battery terminal 6 kΩ or higher
      D47-5 (CANH) - D43-16 (BAT) R - LG ECM Disconnect negative battery terminal 6 kΩ or higher
      D47-16 (CANL) - D43-16 (BAT) W - LG ECM Disconnect negative battery terminal 6 kΩ or higher
      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 TO B+ IN CAN BUS WIRE (ECM MAIN WIRE) Click here

    D

    CHECK FOR SHORT TO B+ IN CAN BUS WIRE (CAN JUNCTION CONNECTOR RH) Click here

    A

  2. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (CAN JUNCTION CONNECTOR CTR)


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

      A017BAHE24
      Standard resistance
      Tester Connection Wiring Color Connected to Condition Specified Condition
      D47-2 (CANH) - D43-16 (BAT) G - LG Yaw rate sensor Disconnect negative battery terminal 6 kΩ or higher
      D47-13 (CANL) - D43-16 (BAT) W - LG Yaw rate sensor Disconnect negative battery terminal 6 kΩ or higher
      D47-3 (CANH) - D43-16 (BAT) Y - LG Center airbag sensor assembly Disconnect negative battery terminal 6 kΩ or higher
      D47-14 (CANL) - D43-16 (BAT) W - LG Center airbag sensor assembly Disconnect negative battery terminal 6 kΩ or higher
      D47-6 (CANH) - D43-16 (BAT) P - LG Air conditioning amplifier Disconnect negative battery terminal 6 kΩ or higher
      D47-17 (CANL) - D43-16 (BAT) W - LG Air conditioning amplifier Disconnect negative battery terminal 6 kΩ or higher
      D47-8 (CANH) - D43-16 (BAT) GR - LG Main body ECU Disconnect negative battery terminal 6 kΩ or higher
      D47-19 (CANL) - D43-16 (BAT) W - LG Main body ECU Disconnect negative battery terminal 6 kΩ 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 TO B+ IN CAN BUS WIRE (YAW RATE SENSOR BRANCH WIRE) Click here

    C

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

    D

    CHECK FOR SHORT TO B+ IN CAN BUS WIRE (AIR CONDITIONING AMPLIFIER BRANCH WIRE) Click here

    E

    CHECK FOR SHORT TO B+ IN CAN BUS WIRE (MAIN BODY ECU BRANCH WIRE) Click here

    A

    REPLACE CAN JUNCTION CONNECTOR CTR

  3. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (ECM MAIN WIRE)


    1. A017FZ5E01

      Disconnect the ECM connector.

    2. A017E4AE08

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D47-5 (CANH) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ or higher
      D47-16 (CANL) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ or higher

    NG

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

    OK

    REPLACE ECM Click here

  4. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (CAN JUNCTION CONNECTOR RH)


    1. Disconnect the CAN junction connector RH

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

      A017BAHE25

      Tech Tips

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

      Standard resistance
      Tester Connection Wiring Color Connected to Condition Specified Condition
      D51-3 (CANH) - D43-16 (BAT) P - LG Combination meter Disconnect negative battery terminal 6 kΩ or higher
      D51-14 (CANL) - D43-16 (BAT) W - LG Combination meter Disconnect negative battery terminal 6 kΩ or higher
      D51-5 (CANH) - D43-16 (BAT) SB - LG CAN junction connector CTR Disconnect negative battery terminal 6 kΩ or higher
      D51-16 (CANL) - D43-16 (BAT) W - LG CAN junction connector CTR Disconnect negative battery terminal 6 kΩ or higher
      Result
      Result Proceed to
      OK A
      NG (Combination meter main wire) B
      NG (CAN junction connector CTR main wire) C

    B

    CHECK FOR SHORT TO B+ IN CAN BUS WIRE (COMBINATION METER 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 TO B+ IN CAN BUS WIRE (CAN JUNCTION CONNECTOR RH)


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

      A017BAHE26
      Standard resistance
      Tester Connection Wiring Color Connected to Condition Specified Condition
      D51-1 (CANH) - D43-16 (BAT) R - LG Steering angle sensor Disconnect negative battery terminal 6 kΩ or higher
      D51-12 (CANL) - D43-16 (BAT) W - LG Steering angle sensor Disconnect negative battery terminal 6 kΩ or higher
      D51-2 (CANH) - D43-16 (BAT) L - LG Power steering ECU Disconnect negative battery terminal 6 kΩ or higher
      D51-13 (CANL) - D43-16 (BAT) W - LG Power steering ECU Disconnect negative battery terminal 6 kΩ or higher
      D51-4 (CANH) - D43-16 (BAT) B - LG Skid control ECU Disconnect negative battery terminal 6 kΩ or higher
      D51-15 (CANL) - D43-16 (BAT) W - LG Skid control ECU Disconnect negative battery terminal 6 kΩ or higher
      Result
      Result Proceed to
      OK A
      NG (Steering angle sensor branch wire) B
      NG (Power steering ECU branch wire) C
      NG (Skid control ECU branch wire) D

    B

    CHECK FOR SHORT TO B+ IN CAN BUS WIRE (STEERING ANGLE SENSOR BRANCH WIRE) Click here

    C

    CHECK FOR SHORT TO B+ IN CAN BUS WIRE (POWER STEERING ECU BRANCH WIRE) Click here

    D

    CHECK SHORT TO B+ IN CAN BUS WIRE (SKID CONTROL ECU BRANCH WIRE) Click here

    A

    REPLACE CAN JUNCTION CONNECTOR RH

  6. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (COMBINATION METER MAIN WIRE)


    1. A017C2ZE01

      Disconnect the combination meter connector.

    2. A017E4AE24

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D51-3 (CANH) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ or higher
      D51-14 (CANL) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ or higher

    NG

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

    OK

    REPLACE COMBINATION METER Click here

  7. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (YAW RATE SENSOR BRANCH WIRE)


    1. A017DEAE04

      Disconnect the yaw rate sensor connector.

    2. A017E4AE06

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D47-2 (CANH) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ or higher
      D47-13 (CANL) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ 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 TO B+ IN CAN BUS WIRE (CENTER AIRBAG SENSOR ASSEMBLY BRANCH WIRE)


    1. A017DMZE22

      Disconnect the center airbag sensor assembly connector.

    2. A017E4AE07

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D47-3 (CANH) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ or higher
      D47-14 (CANL) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ or higher

    NG

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

    OK

    REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here

  9. CHECK FOR SHORT TO B+ IN CAN BUS WIRE (AIR CONDITIONING AMPLIFIER BRANCH WIRE)


    1. A017FS6E06

      Disconnect the air conditioning amplifier connector.

    2. A017E4AE62

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D47-6 (CANH) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ or higher
      D47-17 (CANL) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ 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 TO B+ IN CAN BUS WIRE (MAIN BODY ECU BRANCH WIRE)


    1. A017F33E05

      Disconnect the main body ECU connector.

    2. A017E4AE10

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D47-8 (CANH) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ or higher
      D47-19 (CANL) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ 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 TO B+ IN CAN BUS WIRE (STEERING ANGLE SENSOR BRANCH WIRE)


    1. A017FNVE03

      Disconnect the steering angle sensor connector.

    2. A017E4AE26

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D51-1 (CANH) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ or higher
      D51-12 (CANL) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ 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 TO B+ IN CAN BUS WIRE (POWER STEERING ECU BRANCH WIRE)


    1. A017BE3E11

      Disconnect the power steering ECU connector.

    2. A017E4AE36

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D51-2 (CANH) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ or higher
      D51-13 (CANL) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ 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 SHORT TO B+ IN CAN BUS WIRE (SKID CONTROL ECU BRANCH WIRE)


    1. A017C50E48

      Disconnect the skid control ECU connector.

    2. A017E4AE12

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D51-4 (CANH) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ or higher
      D51-15 (CANL) - D43-16 (BAT) Disconnect negative battery terminal 6 kΩ or higher

    NG

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

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here