CAN COMMUNICATION SYSTEM, Diagnostic DTC:U1002 (CAN MS BUS)

DTC Code DTC Name
U1002 (CAN MS BUS) Lost Communication with Gateway Module (Main body ECU)

DESCRIPTION


DTC No. DTC Detection Condition Trouble Area
U1002 Main body ECU cannot receive signals from all ECUs that have been memorized as those connected to the CAN MS bus.

  • Open or short in CAN MS bus main wire or connector

  • Open or short in CAN MS bus branch wire or connector

  • Main body ECU

  • Certification ECU

  • Back door ECU

  • CAN junction connector RR

WIRING DIAGRAM

A017G7YE05
A017DB0E05

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 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 any doors need to be opened in order to check 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 VEHICLE TYPE

    Result
    Result Proceed to
    w/o Power back door A
    w/ Power back door B

    B

    CHECK CAN MS BUS WIRE Click here

    A

  2. CHECK CAN MS BUS WIRE


    1. Turn the ignition switch off.

    2. Disconnect the certification ECU connector.

    3. A017BXQE07

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

      Standard resistance
      Tester Connection Condition Specified Condition Result
      D36-27 (CANH) - D36-28 (CANL) Ignition switch off 108 to 132 Ω Below 108 Ω: Short in line
      133 Ω or more: Open in CAN main bus line
      D36-27 (CANH) - D36-17 (E) Ignition switch off 200 Ω or higher Below 200 Ω: Ground short
      D36-28 (CANL) - D36-17 (E)
      D36-27 (CANH) - D36-1 (+B) Negative battery terminal disconnected 6 kΩ or higher Below 6 kΩ: +B short
      D36-28 (CANL) - D36-1 (+B)
      Result
      Result Proceed to
      OK A
      Open in CAN main wire B
      Short in line, Ground short, +B short C

    B

    CHECK FOR OPEN IN CAN MS BUS MAIN WIRE Click here

    C

    CHECK FOR SHORT IN CAN MS BUS WIRES Click here

    A

  3. CHECK CAN MS BUS WIRE


    1. Reconnect the certification ECU connector.

    2. Disconnect the main body ECU connector.

    3. A017EWOE04

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D8-16 (CANP) - D8-15 (CANN) Ignition switch off 108 to 132 Ω
      D8-16 (CANP) - D43-4 (CG) Ignition switch off 200 Ω or higher
      D8-15 (CANN) - D43-4 (CG)
      D8-16 (CANP) - D43-16 (BAT) Negative battery terminal disconnected 6 kΩ or higher
      D8-15 (CANN) - D43-16 (BAT)

    NG

    REPLACE CERTIFICATION ECU

    OK

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (MAIN BODY ECU)

  4. CHECK FOR OPEN IN CAN MS BUS MAIN WIRE


    1. Reconnect the certification ECU connector.

    2. Disconnect the main body ECU connector.

    3. A017F33E04

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D8-16 (CANP) - D8-15 (CANN) Ignition switch off 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR (MAIN BODY ECU - CERTIFICATION ECU)

    OK

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (MAIN BODY ECU)

  5. CHECK FOR SHORT IN CAN MS BUS WIRES


    1. Reconnect the certification ECU connector.

    2. Disconnect the main body ECU connector (D8).

    3. A017EWOE04

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D8-16 (CANP) - D8-15 (CANN) Ignition switch off 108 to 132 Ω
      D8-16 (CANP) - D43-4 (CG) Ignition switch off 200 Ω or higher
      D8-15 (CANN) - D43-4 (CG)
      D8-16 (CANP) - D43-16 (BAT) Negative battery terminal disconnected 6 kΩ or higher
      D8-15 (CANN) - D43-16 (BAT)

    NG

    REPAIR OR REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR (MAIN BODY ECU - CERTIFICATION ECU)

    OK

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (MAIN BODY ECU)

  6. CHECK CAN MS BUS WIRE


    1. Turn the ignition switch off.

    2. A017BXME02

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

      Standard resistance
      Tester Connection Condition Specified Condition Result
      O14-6 (MPX1) - O14-5 (MPX2) Ignition switch off 54 to 69 Ω Below 54 Ω: Short in line
      70 Ω or more: Open in CAN main bus line
      O14-6 (MPX1) - O14-11 (GND) Ignition switch off 200 Ω or higher Below 200 Ω: Ground short
      O14-5 (MPX2) - O14-11 (GND)
      O14-6 (MPX1) - O14-12 (B) Negative battery terminal disconnected 6 kΩ or higher Below 6 kΩ: +B short
      O14-5 (MPX2) - O14-12 (B)
      Result
      Result Proceed to
      OK A
      Open in CAN main wire B
      Short in line, Ground short, +B short C

    B

    CHECK FOR OPEN IN CAN MS BUS MAIN WIRE Click here

    C

    CHECK FOR SHORT IN CAN MS BUS WIRES Click here

    A

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (MAIN BODY ECU)

  7. CHECK FOR OPEN IN CAN MS BUS MAIN WIRE


    1. A017F14E06

      Disconnect the main body ECU junction connector from the CAN junction connector RR.

    2. A017FDDE04

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

      Standard resistance
      Tester Connection Condition Specified Condition
      O14-6 (MPX1) - O14-5 (MPX2) Ignition switch off 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (w/o Smart entry and start system) B
      NG (w/ Smart entry and start system) C

    B

    REPLACE CAN JUNCTION CONNECTOR RR

    C

    CHECK FOR OPEN IN CAN MS BUS MAIN WIRE Click here

    A

  8. CHECK FOR OPEN IN CAN MS BUS MAIN WIRE


    1. Reconnect the main body ECU junction connector to the CAN junction connector RR.

    2. Disconnect the main body ECU connector from the main body ECU.

    3. A017F33E04

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D8-16 (CANP) - D8-15 (CANN) Ignition switch off 108 to 132 Ω

    NG

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

    OK

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (MAIN BODY ECU)

  9. CHECK FOR OPEN IN CAN MS BUS MAIN WIRE


    1. Reconnect the main body ECU junction connector to the CAN junction connector RR.

    2. Disconnect the certification ECU connector from the certification ECU.

    3. A017BXQE07

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D36-27 (CANH) - D36-28 (CANL) Ignition switch off 108 to 132 Ω

    NG

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

    OK

    REPLACE CERTIFICATION ECU

  10. CHECK FOR SHORT IN CAN MS BUS WIRES


    1. Disconnect the back door ECU connector.

    2. A017FDDE04

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

      Standard resistance
      Tester Connection Condition Specified Condition
      O14-6 (MPX1) - O14-5 (MPX2) Ignition switch off 54 to 69 Ω
      O14-6 (MPX1) - O14-11 (GND) Ignition switch off 200 Ω or higher
      O14-5 (MPX2) - O14-11 (GND)
      O14-6 (MPX1) - O14-12 (B) Negative battery terminal disconnected 6 kΩ or higher
      O14-5 (MPX2) - O14-12 (B)

    NG

    CHECK FOR SHORT IN CAN MS BUS WIRES Click here

    OK

    REPLACE BACK DOOR MOTOR UNIT (BACK DOOR ECU) Click here

  11. CHECK FOR SHORT IN CAN MS BUS WIRES


    1. A017F14E07

      Disconnect the back door ECU junction connector from the CAN junction connector RR.

    2. A017FDDE04

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

      Standard resistance
      Tester Connection Condition Specified Condition
      O14-6 (MPX1) - O14-5 (MPX2) Ignition switch off 1 MΩ or higher
      O14-6 (MPX1) - O14-11 (GND) Ignition switch off 200 Ω or higher
      O14-5 (MPX2) - O14-11 (GND)
      O14-6 (MPX1) - O14-12 (B) Negative battery terminal disconnected 6 kΩ or higher
      O14-5 (MPX2) - O14-12 (B)

    NG

    REPAIR OR REPLACE CAN MS BUS BRANCH WIRE OR CONNECTOR (BACK DOOR ECU)

    OK

  12. CHECK FOR SHORT IN CAN MS BUS WIRES


    1. Reconnect the back door ECU junction connector from the CAN junction connector RR.

    2. A017F14E06

      Disconnect the main body ECU junction connector from the CAN junction connector RR.

    3. A017FDDE04

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

      Standard resistance
      Tester Connection Condition Specified Condition
      O14-6 (MPX1) - O14-5 (MPX2) Ignition switch off 108 to 132 Ω
      O14-6 (MPX1) - O14-11 (GND) Ignition switch off 200 Ω or higher
      O14-5 (MPX2) - O14-11 (GND)
      O14-6 (MPX1) - O14-12 (B) Negative battery terminal disconnected 6 kΩ or higher
      O14-5 (MPX2) - O14-12 (B)
      Result
      Result Proceed to
      OK A
      NG (w/o Smart entry and start system) B
      NG (w/ Smart entry and start system) C

    B

    REPLACE CAN JUNCTION CONNECTOR RR

    C

    CHECK FOR SHORT IN CAN MS BUS WIRES Click here

    A

  13. CHECK FOR SHORT IN CAN BUS MAIN WIRE


    1. Reconnect the main body ECU junction connector to the CAN junction connector RR.

    2. Disconnect the main body ECU connector from the main body ECU.

    3. A017EWOE04

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D8-16 (CANP) - D8-15 (CANN) Ignition switch off 108 to 132 Ω
      D8-16 (CANP) - D43-4 (CG) Ignition switch off 200 Ω or higher
      D8-15 (CANN) - D43-4 (CG)
      D8-16 (CANP) - D43-16 (BAT) Negative battery terminal disconnected 6 kΩ or higher
      D8-15 (CANN) - D43-16 (BAT)

    NG

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

    OK

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (MAIN BODY ECU)

  14. CHECK FOR SHORT IN CAN MS BUS WIRES


    1. Reconnect the main body ECU junction connector to the CAN junction connector RR.

    2. A017F14E05

      Disconnect the certification ECU junction connector from the CAN junction connector RR.

    3. A017FDDE04

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

      Standard resistance
      Tester Connection Condition Specified Condition
      O14-6 (MPX1) - O14-5 (MPX2) Ignition switch off 108 to 132 Ω
      O14-6 (MPX1) - O14-11 (GND) Ignition switch off 200 Ω or higher
      O14-5 (MPX2) - O14-11 (GND)
      O14-6 (MPX1) - O14-12 (B) Negative battery terminal disconnected 6 kΩ or higher
      O14-5 (MPX2) - O14-12 (B)

    NG

    REPLACE CAN JUNCTION CONNECTOR RR

    OK

  15. CHECK FOR SHORT IN CAN MS BUS WIRES


    1. Reconnect the certification ECU junction connector to the CAN junction connector RR.

    2. Disconnect the certification ECU connector from the certification ECU.

    3. A017BXQE07

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D36-27 (CANH) - D36-28 (CANL) Ignition switch off 108 to 132 Ω
      D36-27 (CANH) - D36-17 (E) Ignition switch off 200 Ω or higher
      D36-28 (CANL) - D36-17 (E)
      D36-27 (CANH) - D36-1 (+B) Negative battery terminal disconnected 6 kΩ or higher
      D36-28 (CANL) - D36-1 (+B)

    NG

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

    OK

    REPLACE CERTIFICATION ECU