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

DTC Code DTC Name
U1002 Lost Communication with Gateway Module (Sensor Bus)

DESCRIPTION


DTC No. Detection Item DTC Detection Condition Trouble Area DTC Output from
U1002 Lost Communication with Gateway Module (Sensor Bus) Driving support ECU assembly cannot receive signals from all ECUs that have been memorized as those connected to local bus.

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

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

  • Driving support ECU assembly

  • Millimeter wave radar sensor assembly

  • Forward recognition camera

  • No. 8 CAN junction connector

 Driving support ECU assembly

WIRING DIAGRAM

B0029JUE13
*a Driving Support ECU Assembly
*b Forward Recognition Camera
*c Millimeter Wave Radar Sensor Assembly
*d No. 8 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

  • After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

  • 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

Tech Tips


  • Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  • 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 LOCAL BUS


    1. B002A7EC08
      *a

      Component with harness connected

      (Driving Support ECU Assembly)
      *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
      G168-8 (CA1P) - G168-9 (CA1N) Cable disconnected from negative (-) battery terminal 54 to 69 Ω Below 53 Ω: Short in line
      G168-8 (CA1P) - G168-9 (CA1N) Cable disconnected from negative (-) battery terminal 54 to 69 Ω Higher than 70 Ω: Open in CAN main bus line
      G168-8 (CA1P) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ: +B short
      G168-9 (CA1N) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ: +B short
      G168-8 (CA1P) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω: Ground short
      G168-9 (CA1N) - G14-4 (CG) 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. 8 CAN JUNCTION CONNECTOR) Click here

    C

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

    D

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

    A

  2. CHECK FOR DTC


    1. Clear the DTCs.


      Body Electrical > Pre-Crash 2 > Clear DTCs

    2. Check for DTCs.


      Body Electrical > Pre-Crash 2 > Trouble Codes
      Result
      Result Proceed to
      DTC U1002 is output from driving support ECU assembly A
      Other DTC is output B

    A

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

    B

    GO TO DIAGNOSTIC TROUBLE CODE CHART Click here

  3. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 8 CAN JUNCTION CONNECTOR)


    1. B002A1HC89
      *a

      Rear view of wire harness connector

      (to No. 8 CAN Junction Connector)
      *b to Forward Recognition Camera
      *c to Millimeter Wave Radar Sensor Assembly

      Disconnect the No. 8 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G173-6 (CANH) - G173-17 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      G173-7 (CANH) - G173-18 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (to forward recognition camera CAN main wire) B
      NG (to millimeter wave radar sensor assembly CAN main wire) C

    A

    REPLACE NO. 8 CAN JUNCTION CONNECTOR

    C

    CONNECT CONNECTOR Click here

    B

  4. CONNECT CONNECTOR


    1. Reconnect the G173 No. 8 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK FOR SHORT IN CAN BUS WIRES (FORWARD RECOGNITION CAMERA - NO. 8 CAN JUNCTION CONNECTOR)


    1. B0029VWC36
      *a

      Front view of wire harness connector

      (to Forward Recognition Camera)

      Disconnect the forward recognition camera connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q17-6 (CANH) - Q17-12 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FORWARD RECOGNITION CAMERA Click here

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (FORWARD RECOGNITION CAMERA - NO. 8 CAN JUNCTION CONNECTOR)

  6. CONNECT CONNECTOR


    1. Reconnect the G173 No. 8 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  7. CHECK FOR OPEN IN CAN BUS MAIN WIRE (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - NO. 8 CAN JUNCTION CONNECTOR)


    1. B0029J1C30
      *a

      Front view of wire harness connector

      (to Millimeter Wave Radar Sensor Assembly)

      Disconnect the millimeter wave radar sensor assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Z6-5 (CA1P) - Z6-6 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - NO. 8 CAN JUNCTION CONNECTOR)

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


    1. B002A1HC90
      *a

      Rear view of wire harness connector

      (to No. 8 CAN Junction Connector)
      *b to Driving Support ECU Assembly
      *c to Forward Recognition Camera
      *d to Millimeter Wave Radar Sensor Assembly

      Disconnect the No. 8 CAN junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G173-5 (CANH) - G173-16 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      G173-6 (CANH) - G173-17 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      G173-7 (CANH) - G173-18 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (to forward recognition camera CAN main wire) B
      NG (to millimeter wave radar sensor assembly CAN main wire) C
      NG (to driving support ECU assembly CAN branch wire) D

    A

    REPLACE NO. 8 CAN JUNCTION CONNECTOR

    C

    CONNECT CONNECTOR Click here

    D

    CONNECT CONNECTOR Click here

    B

  9. CONNECT CONNECTOR


    1. Reconnect the G173 No. 8 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  10. CHECK FOR SHORT IN CAN BUS WIRES (FORWARD RECOGNITION CAMERA - NO. 8 CAN JUNCTION CONNECTOR)


    1. B0029VWC36
      *a

      Front view of wire harness connector

      (to Forward Recognition Camera)

      Disconnect the forward recognition camera connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q17-6 (CANH) - Q17-12 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FORWARD RECOGNITION CAMERA Click here

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (FORWARD RECOGNITION CAMERA - NO. 8 CAN JUNCTION CONNECTOR)

  11. CONNECT CONNECTOR


    1. Reconnect the G173 No. 8 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  12. CHECK FOR SHORT IN CAN BUS WIRES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - NO. 8 CAN JUNCTION CONNECTOR)


    1. B0029J1C30
      *a

      Front view of wire harness connector

      (to Millimeter Wave Radar Sensor Assembly)

      Disconnect the millimeter wave radar sensor assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Z6-5 (CA1P) - Z6-6 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - NO. 8 CAN JUNCTION CONNECTOR)

  13. CONNECT CONNECTOR


    1. Reconnect the G173 No. 8 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  14. CHECK FOR SHORT IN CAN BUS WIRES (DRIVING SUPPORT ECU ASSEMBLY - NO. 8 CAN JUNCTION CONNECTOR)


    1. B002A92C07
      *a

      Front view of wire harness connector

      (to Driving Support ECU Assembly)

      Disconnect the driving support ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G168-8 (CA1P) - G168-9 (CA1N) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - NO. 8 CAN JUNCTION CONNECTOR)

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


    1. Disconnect the No. 8 CAN junction connector.

      B002AI3C46
      *a

      Rear view of wire harness connector

      (to No. 8 CAN Junction Connector)

      		 *b Front view of DLC3
      *c to Driving Support ECU Assembly *d to Forward Recognition Camera
      *e to Millimeter Wave Radar Sensor Assembly - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G173-5 (CANH) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      G173-16 (CANL) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      G173-5 (CANH) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      G173-16 (CANL) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      G173-6 (CANH) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      G173-17 (CANL) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      G173-6 (CANH) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      G173-17 (CANL) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      G173-7 (CANH) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      G173-18 (CANL) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      G173-7 (CANH) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      G173-18 (CANL) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      Result
      Result Proceed to
      OK A
      NG (to forward recognition camera CAN main wire) B
      NG (to millimeter wave radar sensor assembly CAN main wire) C
      NG (to driving support ECU assembly CAN branch wire) D

    A

    REPLACE NO. 8 CAN JUNCTION CONNECTOR

    C

    CONNECT CONNECTOR Click here

    D

    CONNECT CONNECTOR Click here

    B

  16. CONNECT CONNECTOR


    1. Reconnect the G173 No. 8 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  17. CHECK FOR SHORT IN CAN BUS WIRES (FORWARD RECOGNITION CAMERA - NO. 8 CAN JUNCTION CONNECTOR)


    1. B002AIIC13
      *a

      Front view of wire harness connector

      (to Forward Recognition Camera)
      *b Front view of DLC3

      Disconnect the forward recognition camera connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q17-6 (CANH) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      Q17-12 (CANL) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      Q17-6 (CANH) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      Q14-12 (CANL) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FORWARD RECOGNITION CAMERA Click here

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (FORWARD RECOGNITION CAMERA - NO. 8 CAN JUNCTION CONNECTOR)

  18. CONNECT CONNECTOR


    1. Reconnect the G173 No. 8 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  19. CHECK FOR SHORT IN CAN BUS WIRES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - NO. 8 CAN JUNCTION CONNECTOR)


    1. B002AKNC04
      *a

      Front view of wire harness connector

      (to Millimeter Wave Radar Sensor Assembly)
      *b Front view of DLC3

      Disconnect the millimeter wave radar sensor assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Z6-5 (CA1P) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      Z6-6 (CA1N) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      Z6-5 (CA1P) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      Z6-6 (CA1N) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here

    NG

    REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - NO. 8 CAN JUNCTION CONNECTOR)

  20. CONNECT CONNECTOR


    1. Reconnect the G173 No. 8 CAN junction connector.

      Result
      Proceed to
      NEXT

    NEXT

  21. CHECK FOR SHORT IN CAN BUS WIRES (DRIVING SUPPORT ECU ASSEMBLY - NO. 8 CAN JUNCTION CONNECTOR)


    1. B00299BC03
      *a

      Front view of wire harness connector

      (to Driving Support ECU Assembly)
      *b Front view of DLC3

      Disconnect the driving support ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G168-8 (CA1P) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      G168-9 (CA1N) - G14-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      G168-8 (CA1P) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      G168-9 (CA1N) - G14-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - NO. 8 CAN JUNCTION CONNECTOR)