CAN COMMUNICATION SYSTEM, Diagnostic DTC:U1002

DTC Code DTC Name
U1002 Lost Communication with Gateway Module (Power Management1)

DESCRIPTION


DTC No. DTC Detection Condition Trouble Area
U1002 Power management control ECU cannot receive signals from all ECUs that have been memorized as those connected to the CAN No. 2 bus.

  • Open or short in CAN No. 2 bus main wire or connector

  • Open or short in CAN No. 2 bus branch wire or connector

  • AFS ECU

  • Power management control ECU

  • CAN No. 3 junction connector

WIRING DIAGRAM

A01EMBNE03

INSPECTION PROCEDURE

Note


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

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

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

PROCEDURE


  1. CHECK CAN NO. 2 BUS WIRE


    1. Turn the ignition switch off.

    2. A01EJDNE01
      Text in Illustration
      *1

      Component with harness connected

      (CAN No. 3 Junction Connector)
      *2 Earth Terminal
      *3 DLC3

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

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      D69-1 (CANH) - D69-2 (CANL) Ignition switch off 54 to 69 Ω

      Below 54 Ω:

      Short circuit between bus lines

      70 Ω or higher:

      Open circuit in a main bus line
      D69-1 (CANH) - D1-4 (CG) Ignition switch off 200 Ω or higher

      Below 200 Ω:

      CANH ground short
      D69-2 (CANL) - D1-4 (CG) Ignition 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
      D69-1 (CANH) - D1-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANH +B short
      D69-2 (CANL) - D1-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANL +B short
      Result
      Result Proceed to
      OK A
      Open in CAN main bus line B

      • Short circuit between bus lines

      • Ground short

      • +B short

      		 C

    B

    CHECK FOR OPEN IN CAN NO. 2 BUS MAIN WIRE (CAN NO. 3 J/C) Click here

    C

    CHECK FOR SHORT IN CAN NO. 2 BUS WIRE (CAN NO. 3 J/C) Click here

    A

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

  2. CHECK FOR OPEN IN CAN NO. 2 BUS MAIN WIRE (CAN NO. 3 J/C)


    1. A01EIRTE01
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to CAN No. 3 Junction Connector)
      *2 Earth Terminal
      *3 Red
      *4 White

      Disconnect the CAN No. 3 junction connector (D69).

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D69-1 (CANH) - D69-2 (CANL) Ignition switch off 108 to 132 Ω

    NG

    CHECK FOR OPEN IN CAN NO. 2 BUS MAIN WIRE (POWER MANAGEMENT CONTROL ECU) Click here

    OK

    REPLACE CAN NO. 3 J/C

  3. CHECK FOR OPEN IN CAN NO. 2 BUS MAIN WIRE (POWER MANAGEMENT CONTROL ECU)


    1. Reconnect the CAN No. 3 junction connector (D69).

    2. A01ELA6E13
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Disconnect the power management control ECU connector (D43).

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D43-26 (CA2H) - D43-25 (CA2L) Ignition switch off 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN NO. 2 BUS MAIN WIRE OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - CAN NO. 3 J/C)

    OK

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

  4. CHECK FOR SHORT IN CAN NO. 2 BUS WIRE (CAN NO. 3 J/C)


    1. A01EJ4IE02
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to CAN No. 3 Junction Connector)
      *2 Earth Terminal
      *3 DLC3
      *4 Red
      *5 White

      Disconnect the CAN No. 3 junction connector (D69).

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      D69-1 (CANH) - D69-2 (CANL) Ignition switch off 108 to 132 Ω Inspection for open or short circuit between bus line
      D69-1 (CANH) - D1-4 (CG) Ignition switch off 200 Ω or higher Inspection for CANH ground short
      D69-2 (CANL) - D1-4 (CG) Ignition switch off 200 Ω or higher Inspection for CANL ground short
      D69-1 (CANH) - D1-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      D69-2 (CANL) - D1-16 (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 (open or short circuit) that was obtained in the Check CAN No. 2 Bus Wire inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN No. 2 Bus Wire inspection.


    NG

    CHECK FOR SHORT IN CAN NO. 2 BUS WIRE (POWER MANAGEMENT CONTROL ECU) Click here

    OK

  5. CHECK FOR SHORT IN CAN NO. 2 BUS WIRE (AFS ECU)


    1. Reconnect the CAN No. 3 junction connector (D69).

    2. Disconnect the AFS ECU connector.

      A01ELYOE10
      Text in Illustration
      *1 Front view of wire harness connector (to AFS ECU)
      *2 DLC3

    3. Measure the resistance of the wire harness side connectors.

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      D44-12 (CANH) - D44-13 (CANL) Ignition switch off 54 to 69 Ω Inspection for open or short circuit between bus line
      D44-12 (CANH) - D44-22 (E1) Ignition switch off 200 Ω or higher Inspection for CANH ground short
      D44-13 (CANL) - D44-22 (E1) Ignition switch off 200 Ω or higher Inspection for CANL ground short
      D44-12 (CANH) - D1-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      D44-13 (CANL) - D1-16 (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 (open or short circuit) that was obtained in the Check CAN No. 2 Bus Wire inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN No. 2 Bus Wire inspection.


    NG

    CHECK CAN NO. 2 BUS BRANCH WIRE (AFS ECU) Click here

    OK

    REPLACE AFS ECU Click here

  6. CHECK CAN NO. 2 BUS BRANCH WIRE (AFS ECU)


    1. A01EIT7E07
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to CAN No. 3 Junction Connector)
      *2 Earth Terminal
      *3 Yellow
      *4 White

      Disconnect the CAN No. 3 junction connector (D70).

    2. Measure the resistance of the wire harness side connectors.

      A01ELYOE10
      Text in Illustration
      *1 Front view of wire harness connector (to AFS ECU)
      *2 DLC3
      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      D44-12 (CANH) - D44-13 (CANL) Ignition switch off 1 MΩ or higher Inspection for open or short circuit between bus line
      D44-12 (CANH) - D44-22 (E1) Ignition switch off 200 Ω or higher Inspection for CANH ground short
      D44-13 (CANL) - D44-22 (E1) Ignition switch off 200 Ω or higher Inspection for CANL ground short
      D44-12 (CANH) - D1-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      D44-13 (CANL) - D1-16 (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 (open or short circuit) that was obtained in the Check CAN No. 2 Bus Wire inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN No. 2 Bus Wire inspection.


    NG

    REPAIR OR REPLACE CAN NO. 2 BUS BRANCH WIRE OR CONNECTOR (AFS ECU - CAN NO. 3 J/C)

    OK

    REPLACE CAN NO. 3 J/C

  7. CHECK FOR SHORT IN CAN NO. 2 BUS WIRE (POWER MANAGEMENT CONTROL ECU)


    1. Reconnect the CAN No. 3 junction connector (D69).

    2. A01ELA6E14
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Disconnect the power management control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      D43-26 (CA2H) - D43-25 (CA2L) Ignition switch off 108 to 132 Ω Inspection for open or short circuit between bus line
      D43-26 (CA2H) - D43-6 (GND) Ignition switch off 200 Ω or higher Inspection for CANH ground short
      D43-25 (CA2L) - D43-6 (GND) Ignition switch off 200 Ω or higher Inspection for CANL ground short
      D43-26 (CA2H) - D43-1 (AN22) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      D43-25 (CA2L) - D43-1 (AN22) 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 (open or short circuit) that was obtained in the Check CAN No. 2 Bus Wire inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN No. 2 Bus Wire inspection.


    NG

    REPAIR OR REPLACE CAN NO. 2 BUS MAIN WIRE OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - CAN NO. 3 J/C)

    OK

    REPLACE POWER MANAGEMENT CONTROL ECU Click here