CAN COMMUNICATION SYSTEM(for RHD with Central Gateway ECU), Diagnostic DTC:U1002

DTC Code DTC Name
U1002 Lost Communication with Gateway Module

DESCRIPTION


DTC No. Detection Item DTC Detection Condition Trouble Area DTC Output from
U1002 Lost Communication with Gateway Module Lost communication with the gateway module.

  • Open or short in sub bus 1 CAN main wire or connector

  • Open or short in sub bus 1 CAN branch wire or connector

  • Main body ECU (multiplex network body ECU)

  • Multiplex network door ECU

  • No. 5 CAN junction connector

  • No. 1 CAN junction terminal

 Main body ECU (multiplex network body ECU)

WIRING DIAGRAM

A01QU0FE05
*a Multiplex Network Door ECU
*b Main Body ECU (Multiplex Network Body ECU)
*c No. 1 CAN Junction Terminal
*d No. 5 CAN Junction Connector

CAUTION / NOTICE / HINT

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 ignition switch off and leave the vehicle for 1 minute or more without operating the key, switches or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work.

    Click here

  • DTC check procedure: Turn the ignition switch to ON and wait at least 20 seconds.

  • After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed.

    Click here

  • When replacing the main body ECU (multiplex network body ECU), make sure to replace it with a new one.

Tech Tips

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 may help determine the cause of the malfunction.

PROCEDURE


  1. CHECK SUB BUS 1


    1. A01QQOHC09
      *a

      Component with harness connected

      (No. 1 CAN Junction Terminal)
      *b Front view of DLC3

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition Resistance: Malfunction
      N31-3 (CANH) - N31-2 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω Below 53 Ω: Short in line
      N31-3 (CANH) - N31-2 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω Higher than 70 Ω: Open in CAN main bus line
      N31-3 (CANH) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ: +B short
      N31-2 (CANL) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ: +B short
      N31-3 (CANH) - N31-1 (E) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω: Ground short
      N31-2 (CANL) - N31-1 (E) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω: Ground short
      Result
      Result Proceed to
      OK A

      NG

      - Open in CAN main wire

      		 B

      NG

      - Short in CAN bus wire

      		 C

      NG

      - +B short

      - Ground short

      		 D

    B

    CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 5 CAN JUNCTION CONNECTOR) Click here

    C

    CHECK FOR SHORT IN CAN BUS WIRES (NO. 5 CAN JUNCTION CONNECTOR) Click here

    D

    CHECK FOR SHORT IN CAN BUS WIRES (NO. 5 CAN JUNCTION CONNECTOR) Click here

    A

  2. CHECK FOR DTC


    1. Clear the DTCs.


      Body Electrical > Main Body > Clear DTCs

    2. Check for DTCs.


      Body Electrical > Main Body > Trouble Codes
      Result
      Result Proceed to
      DTC U1002 is output from main body ECU (multiplex network body ECU) A
      Other DTC is output B

    A

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    B

    GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

  3. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 5 CAN JUNCTION CONNECTOR)


    1. A01QQOZC79
      *a

      Rear view of wire harness connector

      (to No. 5 CAN Junction Connector)
      *b to Main Body ECU (Multiplex Network Body ECU)
      *c to No. 1 CAN Junction Terminal

      Disconnect the No. 5 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      N32-7 (CANH) - N32-18 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      N32-9 (CANH) - N32-20 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (to No. 1 CAN junction terminal CAN main wire) B
      NG (to main body ECU [multiplex network body ECU] CAN main wire) C

    A

    REPLACE NO. 5 CAN JUNCTION CONNECTOR

    C

    CONNECT CONNECTOR Click here

    B

  4. CONNECT CONNECTOR


    1. Reconnect the No. 5 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 1 CAN JUNCTION TERMINAL - NO. 5 CAN JUNCTION CONNECTOR)


    1. A01QQHDC18
      *a

      Rear view of wire harness connector

      (to No. 1 CAN Junction Terminal)

      Disconnect the No. 1 CAN junction terminal connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      N31-3 (CANH) - N31-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NO. 1 CAN JUNCTION TERMINAL

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 1 CAN JUNCTION TERMINAL - NO. 5 CAN JUNCTION CONNECTOR)

  6. CONNECT CONNECTOR


    1. Reconnect the No. 5 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  7. CHECK FOR OPEN IN CAN BUS MAIN WIRE (MAIN BODY ECU - NO. 5 CAN JUNCTION CONNECTOR)


    1. A01QU4YC01
      *a

      Rear view of wire harness connector

      (to Main Body ECU [Multiplex Network Body ECU])

      Disconnect the main body ECU (multiplex network body ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G79-9 (CANP) - G79-10 (CANN) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTED TO MAIN BODY ECU (MAIN BODY ECU - NO. 5 CAN JUNCTION CONNECTOR)

  8. CHECK FOR SHORT IN CAN BUS WIRES (NO. 5 CAN JUNCTION CONNECTOR)


    1. A01QQOZC80
      *a

      Rear view of wire harness connector

      (to No. 5 CAN Junction Connector)
      *b to Main Body ECU (Multiplex Network Body ECU)
      *c to Multiplex Network Door ECU
      *d to No. 1 CAN Junction Terminal

      Disconnect the No. 5 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      N32-7 (CANH) - N32-18 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      N32-8 (CANH) - N32-19 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      N32-9 (CANH) - N32-20 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (to multiplex network door ECU CAN branch wire) B
      NG (to No. 1 CAN junction terminal CAN main wire) C
      NG (to main body ECU [multiplex network body ECU] CAN main wire) D

    A

    REPLACE NO. 5 CAN JUNCTION CONNECTOR

    C

    CONNECT CONNECTOR Click here

    D

    CONNECT CONNECTOR Click here

    B

  9. CONNECT CONNECTOR


    1. Reconnect the No. 5 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  10. CHECK FOR SHORT IN CAN BUS WIRES (MULTIPLEX NETWORK DOOR ECU)


    1. A01QU2DC10
      *a

      Front view of wire harness connector

      (to Multiplex Network Door ECU)

      Disconnect the multiplex network door ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      U29-39 (CANP) - U29-40 (CANN) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MULTIPLEX NETWORK DOOR ECU Click here

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO MULTIPLEX NETWORK DOOR ECU (CANP, CANN)

  11. CONNECT CONNECTOR


    1. Reconnect the No. 5 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  12. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 CAN JUNCTION TERMINAL)


    1. A01QQHDC18
      *a

      Rear view of wire harness connector

      (to No. 1 CAN Junction Terminal)

      Disconnect the No. 1 CAN junction terminal connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      N31-3 (CANH) - N31-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NO. 1 CAN JUNCTION TERMINAL

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 1 CAN JUNCTION TERMINAL - NO. 5 CAN JUNCTION CONNECTOR)

  13. CONNECT CONNECTOR


    1. Reconnect the No. 5 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  14. CHECK FOR SHORT IN CAN BUS WIRES (MAIN BODY ECU)


    1. A01QU4YC01
      *a

      Rear view of wire harness connector

      (to Main Body ECU [Multiplex Network Body ECU])

      Disconnect the main body ECU (multiplex network body ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G79-9 (CANP) - G79-10 (CANN) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTED TO MAIN BODY ECU (CANP, CANN)

  15. CHECK FOR SHORT IN CAN BUS WIRES (NO. 5 CAN JUNCTION CONNECTOR)


    1. Disconnect the No. 5 CAN junction connector.

      A01QTG9C26
      *a

      Rear view of wire harness connector

      (to No. 5 CAN Junction Connector)

      		 *b Front view of DLC3
      *c to Main Body ECU (Multiplex Network Body ECU) *d to Multiplex Network Door ECU
      *e to No. 1 CAN Junction Terminal - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      N32-7 (CANH) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Main body ECU (multiplex network body ECU)
      N32-18 (CANL) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      N32-7 (CANH) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      N32-18 (CANL) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      N32-8 (CANH) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Multiplex network door ECU
      N32-19 (CANL) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      N32-8 (CANH) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      N32-19 (CANL) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      N32-9 (CANH) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher No. 1 CAN junction terminal
      N32-20 (CANL) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      N32-9 (CANH) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      N32-20 (CANL) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      Result
      Result Proceed to
      OK A
      NG (to multiplex network door ECU CAN branch wire) B
      NG (to No. 1 CAN junction terminal CAN main wire) C
      NG (to main body ECU [multiplex network body ECU] CAN main wire) D

    A

    REPLACE NO. 5 CAN JUNCTION CONNECTOR

    C

    CONNECT CONNECTOR Click here

    D

    CONNECT CONNECTOR Click here

    B

  16. CONNECT CONNECTOR


    1. Reconnect the No. 5 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  17. CHECK FOR SHORT IN CAN BUS WIRES (MULTIPLEX NETWORK DOOR ECU)


    1. A01QSMZC29
      *a

      Rear view of wire harness connector

      (to Multiplex Network Door ECU)
      *b Front view of DLC3

      Disconnect the multiplex network door ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      U29-39 (CANP) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      U29-40 (CANN) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      U29-39 (CANP) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      U29-40 (CANN) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MULTIPLEX NETWORK DOOR ECU Click here

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO MULTIPLEX NETWORK DOOR ECU (CANP, CANN)

  18. CONNECT CONNECTOR


    1. Reconnect the No. 5 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  19. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 CAN JUNCTION TERMINAL)


    1. A01QPXGC04
      *a

      Rear view of wire harness connector

      (to No. 1 CAN Junction Terminal)
      *b Front view of DLC3

      Disconnect the No. 1 CAN junction terminal connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      N31-3 (CANH) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      N31-2 (CANL) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      N31-3 (CANH) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      N31-2 (CANL) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NO. 1 CAN JUNCTION TERMINAL

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 1 CAN JUNCTION TERMINAL - NO. 5 CAN JUNCTION CONNECTOR)

  20. CONNECT CONNECTOR


    1. Reconnect the No. 5 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  21. CHECK FOR SHORT IN CAN BUS WIRES (MAIN BODY ECU)


    1. A01QSO5C01
      *a

      Rear view of wire harness connector

      (to Main Body ECU [Multiplex Network Body ECU])
      *b Front view of DLC3

      Disconnect the main body ECU (multiplex network body ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G79-9 (CANP) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      G79-10 (CANN) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      G79-9 (CANP) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      G79-10 (CANN) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    NG

    REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO MAIN BODY ECU (CANP, CANN)