CAN COMMUNICATION SYSTEM, Diagnostic DTC:U1002

DTC Code DTC Name
U1002 Lost Communication with Gateway Module (Main Body)

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

  • Outer mirror control ECU RH

  • Outer mirror control ECU LH

  • Position control ECU RH

  • Position control ECU LH

  • Power back door ECU

  • CAN No. 6 junction connector

WIRING DIAGRAM

A019MTNE01
A019N0LE03

INSPECTION PROCEDURE

Note


  • Turn the engine switch off before measuring the resistances between CAN bus main wires and between CAN bus branch wires.

  • Turn the engine switch off before inspecting CAN bus wires for a ground short.

  • After the engine 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 engine 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 engine 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 may help determine the cause of the malfunction.

PROCEDURE


  1. CHECK CAN MS BUS WIRE


    1. Turn the engine switch off.

    2. A019NY5E04
      Text in Illustration
      *1

      Component with harness connected

      (Tilt and Telescopic ECU)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition Result
      F36-5 (CANP) - F36-14 (CANN) Engine switch off 54 to 69 Ω

      Below 54 Ω:

      Short circuit between bus wires

      70 Ω or more:

      Open circuit in a main bus wire
      F36-5 (CANP) - F36-11 (GND) Engine switch off 200 Ω or higher

      Below 200 Ω:

      CANH ground short
      F36-14 (CANN) - F36-11 (GND) Engine switch off 200 Ω or higher

      Below 200 Ω:

      CANL ground short

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      F36-5 (CANP) - F36-2 (+B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANH +B short
      F36-14 (CANN) - F36-2 (+B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANL +B short
      Result
      Result Proceed to
      OK A
      Open circuit in CAN main bus wire B
      Short circuit between bus wires C

      • Ground short

      • +B short

      		 D

    B

    CHECK FOR OPEN IN CAN BUS MAIN WIRE (TILT AND TELESCOPIC ECU) Click here

    C

    CHECK FOR SHORT IN CAN MS BUS WIRES (TILT AND TELESCOPIC ECU) Click here

    D

    CHECK FOR SHORT IN CAN MS BUS WIRES (TILT AND TELESCOPIC ECU) Click here

    A

    REPLACE MULTIPLEX NETWORK BODY ECU (MAIN BODY ECU)

  2. CHECK FOR OPEN IN CAN BUS MAIN WIRE (TILT AND TELESCOPIC ECU)


    1. A019LYBE11
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Tilt and Telescopic ECU)

      Disconnect the tilt and telescopic ECU connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F36-5 (CANP) - F36-14 (CANN) Engine switch off 108 to 132 Ω

    NG

    CHECK FOR OPEN IN CAN BUS MAIN WIRE (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU) Click here

    OK

    REPLACE MULTIPLEX TILT AND TELESCOPIC ECU

  3. CHECK FOR OPEN IN CAN BUS MAIN WIRE (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU)


    1. Reconnect the tilt and telescopic ECU connector.

    2. A019JWHE01
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to CAN No. 6 Junction Connector)

      Disconnect the CAN No. 6 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F74-1 (CANH) - F74-2 (CANL) Engine switch off 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU)

    OK

  4. CHECK FOR OPEN IN CAN BUS MAIN WIRE (CAN NO. 6 J/C - MAIN BODY ECU)


    1. A019JWHE02
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to CAN No. 6 Junction Connector)

      Disconnect the CAN No. 6 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F78-1 (CANH) - F78-2 (CANL) Engine switch off 108 to 132 Ω

    NG

    CHECH FOR OPEN IN CAN BUS MAIN WIRE (MAIN BODY ECU) Click here

    OK

    REPLACE CAN NO. 6 JUNCTION CONNECTOR

  5. CHECH FOR OPEN IN CAN BUS MAIN WIRE (MAIN BODY ECU)


    1. Reconnect the CAN No. 6 junction connectors.

    2. A019OAWE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Main Body ECU)

      Disconnect the main body ECU connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F14-9 (CANP) - F14-10 (CANN) Engine switch off 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR (CAN NO. 6 J/C - MAIN BODY ECU)

    OK

    REPLACE MULTIPLEX NETWORK BODY ECU (MAIN BODY ECU)

  6. CHECK FOR SHORT IN CAN MS BUS WIRES (TILT AND TELESCOPIC ECU)


    1. A019LYBE11
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Tilt and Telescopic ECU)

      Disconnect the tilt and telescopic ECU connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F36-5 (CANP) - F36-14 (CANN) Engine switch off 108 to 132 Ω

    NG

    CHECK FOR SHORT IN CAN MS BUS WIRES (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU) Click here

    OK

    REPLACE MULTIPLEX TILT AND TELESCOPIC ECU

  7. CHECK FOR SHORT IN CAN MS BUS WIRES (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU)


    1. Reconnect the tilt and telescopic ECU connector.

    2. A019JWHE01
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to CAN No. 6 Junction Connector)

      Disconnect the CAN No. 6 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F74-1 (CANH) - F74-2 (CANL) Engine switch off 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU)

    OK

  8. CHECK FOR SHORT IN CAN MS BUS WIRES (CAN NO. 6 J/C - MAIN BODY ECU)


    1. A019JWHE02
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to CAN No. 6 Junction Connector)

      Disconnect the CAN No. 6 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F78-1 (CANH) - F78-2 (CANL) Engine switch off 108 to 132 Ω

    NG

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

    OK

  9. CHECK FOR CAN MS BUS BRANCH WIRE


    1. Reconnect the CAN No. 6 junction connectors.

    2. A019NY5E05
      Text in Illustration
      *1

      Component with harness connected

      (Tilt and Telescopic ECU)

      Connect the probes of an ohmmeter to terminals CANP and CANN of the tilt and telescopic ECU.

    3. A019P1QE02
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to CAN No. 6 Junction Connector)

      While observing the resistance value shown on the tester, disconnect branch wire connector (except F74 and F78) from the CAN No. 6 junction connector until the resistance becomes normal (between 54 and 69 Ω).

      Terminal No.

      (Symbol)

      		 Wiring Color Connected to
      F73-1 (CANH) GR Outer mirror control ECU RH
      F73-2 (CANL) W
      F75-1 (CANH) G Position control ECU LH
      F75-2 (CANL) W
      F76-1 (CANH) B Power back door ECU
      F76-2 (CANL) W
      F77-1 (CANH) LG Outer mirror control ECU LH
      F77-2 (CANL) W
      F87-1 (CANH) Y Position control ECU RH
      F87-2 (CANL) W

      Tech Tips


      • The connectors connected to the CAN junction connector can be distinguished by the colors of the bus wire.

      • Reconnecting the connectors to non-specified positions on the CAN junction connector does not affect system operation.

      Result
      Result Proceed to

      The resistance is still below 54 Ω when all the specified connector is disconnected.

      (There is no short in the branch wires.)

      		 A

      The resistance becomes normal (between 54 and 69 Ω) when a connector is disconnected.

      (There is a short in one or more of the branch wires.)

      		 B

    B

    CHECK FOR CAN MS BUS BRANCH WIRE Click here

    A

    REPLACE CAN NO. 6 JUNCTION CONNECTOR

  10. CHECK FOR CAN MS BUS BRANCH WIRE


    1. Reconnect the connector for the short-circuited branch wire to the CAN junction connector (the connector that caused the bus wire resistance to become normal (between 54 and 69 Ω) when it was disconnected).

    2. Disconnect the connector that includes terminals CANH and CANL from the ECU to which the short-circuited branch wire is connected.

    3. A019NY5E05
      Text in Illustration
      *1

      Component with harness connected

      (Tilt and Telescopic ECU)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F36-5 (CANP) - F36-14 (CANN) Engine switch off 54 to 69 Ω

      Tech Tips

      If the resistance becomes normal (between 54 and 69 Ω) when the connector is disconnected from the ECU, there may be a short in the ECU.


    NG

    REPAIR OR REPLACE CAN MS BUS BRANCH WIRE OR CONNECTOR

    OK

    REPLACE CORRESPONDING ECU

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


    1. Reconnect the CAN No. 6 junction connectors.

    2. A019OAWE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Main Body ECU)

      Disconnect the main body ECU connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F14-9 (CANP) - F14-10 (CANL) Engine switch off 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR (CAN NO. 6 J/C - MAIN BODY ECU)

    OK

    REPLACE MULTIPLEX NETWORK BODY ECU (MAIN BODY ECU)

  12. CHECK FOR SHORT IN CAN MS BUS WIRES (TILT AND TELESCOPIC ECU)


    1. A019LYBE14
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Tilt and Telescopic ECU)

      Disconnect the tilt and telescopic ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      F36-5 (CANP) - F36-11 (GND) Engine switch off 200 Ω or higher Inspection for CANH ground short
      F36-14 (CANN) - F36-11 (GND) Engine switch off 200 Ω or higher Inspection for CANL ground short
      F36-5 (CANP) - F36-2 (+B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      F36-14 (CANN) - F36-2 (+B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short

      Tech Tips

      It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check CAN MS Bus Wire inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN MS Bus Wire inspection.


    NG

    CHECK FOR SHORT IN CAN MS BUS WIRES (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU) Click here

    OK

    REPLACE MULTIPLEX TILT AND TELESCOPIC ECU

  13. CHECK FOR SHORT IN CAN MS BUS WIRES (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU)


    1. A019NBME01
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to CAN No. 6 Junction Connector)
      *2 DLC3

      Disconnect the CAN No. 6 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      F74-1 (CANH) - F17-4 (CG) Engine switch off 200 Ω or higher Inspection for CANH ground short
      F74-2 (CANL) - F17-4 (CG) Engine switch off 200 Ω or higher Inspection for CANL ground short
      F74-1 (CANH) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      F74-2 (CANL) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short

      Tech Tips

      It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check CAN MS Bus Wire inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN MS Bus Wire inspection.


    NG

    REPAIR OR REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU)

    OK

  14. CHECK FOR SHORT IN CAN MS BUS WIRES (CAN NO. 6 J/C - MAIN BODY ECU)


    1. A019NBME02
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to CAN No. 6 Junction Connector)
      *2 DLC3

      Disconnect the CAN No. 6 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      F78-1 (CANH) - F17-4 (CG) Engine switch off 200 Ω or higher Inspection for CANH ground short
      F78-2 (CANL) - F17-4 (CG) Engine switch off 200 Ω or higher Inspection for CANL ground short
      F78-1 (CANH) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      F78-2 (CANL) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short

      Tech Tips

      It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check CAN MS Bus Wire inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN MS Bus Wire inspection.


    NG

    CHECK FOR SHORT IN CAN MS BUS WIRES Click here

    OK

  15. CHECK FOR CAN MS BUS BRANCH WIRE


    1. Reconnect the CAN No. 6 junction connectors.

    2. A019NY5E04
      Text in Illustration
      *1

      Component with harness connected

      (Tilt and Telescopic ECU)

      Connect the probes of an ohmmeter to terminals CANP or CANN and GND or +B of the tilt and telescopic ECU.

      Tech Tips

      It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check CAN MS Bus Wire inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN MS Bus Wire inspection.

    3. A019P1QE02
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to CAN No. 6 Junction Connector)

      While observing the resistance value shown on the tester, disconnect branch wire connector (except F74 and F78) from the CAN No. 6 junction connector until the resistance becomes normal (6 kΩ or higher (for +B short) or 200 Ω or higher (for ground short)).

      Terminal No.

      (Symbol)

      		 Wiring Color Connected to
      F73-1 (CANH) GR Outer mirror control ECU RH
      F73-2 (CANL) W
      F75-1 (CANH) G Position control ECU LH
      F75-2 (CANL) W
      F76-1 (CANH) B Power back door ECU
      F76-2 (CANL) W
      F77-1 (CANH) LG Outer mirror control ECU LH
      F77-2 (CANL) W
      F87-1 (CANH) Y Position control ECU RH
      F87-2 (CANL) W

      Tech Tips


      • The connectors connected to the CAN junction connector can be distinguished by the colors of the bus wire.

      • Reconnecting the connectors to non-specified positions on the CAN junction connector does not affect system operation.

      Result
      Result Proceed to

      The resistance between terminals CANP and +B, or the resistance between CANN and +BAT is still below 6 kΩ when all the specified connectors are disconnected from the CAN junction connector.

      (There is no short to +B in the branch wires.)

      		 A

      The resistance between terminals CANP and GND, or the resistance between CANN and GND is still below 200 Ω when all the specified connectors are disconnected from the CAN junction connector.

      (There is no short to GND in the branch wires.)

      The resistance between terminals CANP and +B, or the resistance between CANN and +B becomes normal (6 kΩ or higher) when a connector is disconnected from the CAN junction connector.

      (There is a short to +B in one of the areas related to one or more of the disconnected branch wires.)

      		 B

      The resistance between terminals CANP and GND, or the resistance between CANN and GND becomes normal (200 Ω or higher) when a connector is disconnected from the CAN junction connector.

      (There is a short to GND in one of the areas related to one or more of the disconnected branch wires.)

    B

    CHECK FOR CAN MS BUS BRANCH WIRE Click here

    A

    REPLACE CAN NO. 6 JUNCTION CONNECTOR

  16. CHECK FOR CAN MS BUS BRANCH WIRE


    1. Reconnect the connector for the bus wire that is shorted to +B or GND to the CAN junction connector (the connector that caused the bus wire resistance to change to 6 kΩ or higher (for +B short) or 200 Ω or higher (for ground short) when it was disconnected).

    2. Disconnect the connector that includes terminals CANH and CANL from the ECU to which the bus wire shorted to +B or GND is connected.

    3. A019NY5E04
      Text in Illustration
      *1

      Component with harness connected

      (Tilt and Telescopic ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      F36-5 (CANP) - F36-11 (GND) Engine switch off 200 Ω or higher Inspection for CANH ground short
      F36-14 (CANN) - F36-11 (GND) Engine switch off 200 Ω or higher Inspection for CANL ground short
      F36-5 (CANP) - F36-2 (+B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      F36-14 (CANN) - F36-2 (+B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short

      Tech Tips

      If the resistance becomes normal when the connector is disconnected from the ECU, there may be a short in the ECU.


    NG

    REPAIR OR REPLACE CAN MS BUS BRANCH WIRE OR CONNECTOR

    OK

    REPLACE CORRESPONDING ECU

  17. CHECK FOR SHORT IN CAN MS BUS WIRES


    1. A019P0GE05
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Main Body ECU)
      *2 DLC3

      Disconnect the main body ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      F14-9 (CANP) - F14-3 (GND2) Engine switch off 200 Ω or higher Inspection for CANH ground short
      F14-10 (CANN) - F14-3 (GND2) Engine switch off 200 Ω or higher Inspection for CANL ground short
      F14-9 (CANP) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      F14-10 (CANN) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short

      Tech Tips

      It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check CAN MS Bus Wire inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN MS Bus Wire inspection.


    NG

    REPAIR OR REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR (CAN NO. 6 J/C - MAIN BODY ECU)

    OK

    REPLACE MULTIPLEX NETWORK BODY ECU (MAIN BODY ECU)