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CAN COMMUNICATION SYSTEM, Diagnostic DTC:U1002

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DTC Code DTC Name
U1002 Lost Communication with Gateway Module (Power Management1)
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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 V2 bus.

  • Open or short in V2 bus main line or connector

  • Open or short in V2 bus branch line or connector

  • Power management control ECU

  • Driving support ECU assembly

  • Seat belt control ECU

  • Clearance warning ECU assembly

  • CAN No. 4 junction connector
Tip:

This diagnosis procedure is for when DTC U1002 is output by the power management control ECU (Intelligent tester display: PM1 Gateway).

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WIRING DIAGRAM

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INSPECTION PROCEDURE

Note:

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work (Click here).

  • Turn the power switch off before measuring the resistances between CAN main bus lines and between CAN branch lines.

  • Turn the power switch off before inspecting CAN bus lines for a ground short.

  • After the power 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 power 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.

Tip:

  • Operating the power 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.

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PROCEDURE


  1. Click here

    CHECK V2 BUS LINES


    1. Turn the power switch off.

    2. A003ZTWE03

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition Result
      H3-34 (CA2H) - H3-35 (CA2L) Power 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
      H3-34 (CA2H) - H3-6 (E1) Power switch off 200 Ω or higher

      Below 200 Ω:

      CANH ground short
      H3-35 (CA2L) - H3-6 (E1) Power switch off 200 Ω or higher

      Below 200 Ω:

      CANL ground short
      Table 1. Text in Illustration
      *a

      Component with harness connected

      (Power Management Control ECU)

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      H3-34 (CA2H) - H3-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANH +B short
      H3-35 (CA2L) - H3-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher

      Below 6 kΩ:

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

      • Ground short

      • +B short

      		 D

  2. Click here

    CHECK DTC OUTPUT


    1. Clear the DTCs.

    2. Turn the power switch off.

    3. Turn the power switch on (IG) and recheck for DTCs.

      Result
      Result Proceed to

      U1002 is output from power management control ECU

      (Intelligent tester display: PM1 Gateway)

      		 A
      Other DTC is output B

  3. Click here

    CHECK FOR OPEN IN V2 BUS MAIN LINES (POWER MANAGEMENT CONTROL ECU MAIN WIRE)


    1. A003V8WE30

      Disconnect the power management control ECU connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H3-34 (CA2H) - H3-35 (CA2L) Power switch off 108 to 132 Ω
      Table 2. Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

  4. Click here

    CHECK FOR OPEN IN V2 BUS MAIN LINES (CAN NO. 4 J/C - POWER MANAGEMENT CONTROL ECU)


    1. Reconnect the power management control ECU connector.

    2. A003Y1RE31

      Disconnect the power management control ECU main line connector from the CAN No. 4 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition Connected to
      H106-1 (CANH) - H106-2 (CANL) Power switch off 108 to 132 Ω Power management control ECU
      Table 3. Text in Illustration
      *a

      Rear view of wire harness connector

      (to CAN No. 4 Junction Connector)
      *b to Power Management Control ECU

  5. Click here

    CHECK FOR SHORT IN V2 BUS LINES (POWER MANAGEMENT CONTROL ECU)


    1. A003V8WE30

      Disconnect the power management control ECU connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H3-34 (CA2H) - H3-35 (CA2L) Power switch off 108 to 132 Ω
      Table 4. Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

  6. Click here

    CHECK FOR SHORT IN V2 BUS LINES (CAN NO. 4 J/C - POWER MANAGEMENT CONTROL ECU)


    1. Reconnect the power management control ECU connector.

    2. A003Y1RE31

      Disconnect the power management control ECU main line connector from the CAN No. 4 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition Connected to
      H106-1 (CANH) - H106-2 (CANL) Power switch off 108 to 132 Ω Power management control ECU
      Table 5. Text in Illustration
      *a

      Rear view of wire harness connector

      (to CAN No. 4 Junction Connector)
      *b to Power Management Control ECU

  7. Click here

    CHECK FOR SHORT IN V2 BUS LINES (CAN NO. 4 J/C)


    1. Reconnect the power management control ECU main line connector to the CAN No. 4 junction connector.

    2. A003ZTWE02

      Connect the probes of an ohmmeter to terminals 34 (CA2H) and 35 (CA2L) of the power management control ECU.

      Table 6. Text in Illustration
      *a

      Component with harness connector

      (Power Management Control ECU)
    3. A003X9ZE01

      While observing the resistance value shown on the ohmmeter, disconnect branch line connectors (except H106) from the CAN No. 4 junction connector until the resistance becomes normal (between 54 and 69 Ω).

      Table 7. Text in Illustration
      *1 CAN No. 4 Junction Connector - -
      *a Junction Connector B Side *b Junction Connector A Side
      *c Earth Terminal *d

      Front view of wire harness connector

      (to CAN No. 4 Junction Connector)
      Table 8. Junction Connector A Side
      Terminal No. (Symbol) Wiring Color Connected to
      H111-1 (GND) W-B Body ground
      H106-1 (CANH) R Power management control ECU
      H106-2 (CANL) B
      H107-1 (CANH) G Clearance warning ECU assembly
      H107-2 (CANL) B
      H108-1 (CANH) L Driving support ECU assembly
      H108-2 (CANL) B
      H109-1 (CANH) Y Seat belt control ECU
      H109-2 (CANL) B
      Tip:

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

      • 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 connectors are disconnected.

        (There is no short in the branch lines.)

        		 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 lines.)

        		 B

  8. Click here

    CHECK FOR SHORT IN V2 BUS LINES (ECUS)


    1. Reconnect the connector for the short-circuited branch line to the CAN junction connector (the connector that caused the bus line 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 line is connected.

    3. A003ZTWE02

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      H3-34 (CA2H) - H3-35 (CA2L) Power switch off 54 to 69 Ω
      Table 9. Text in Illustration
      *a

      Component with harness connector

      (Power Management Control ECU)
      Tip:

      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.


  9. Click here

    CHECK FOR SHORT IN V2 BUS LINE (POWER MANAGEMENT CONTROL ECU)


    1. A003V8WE31

      Disconnect the power management control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      H3-34 (CA2H) - H3-6 (E1) Power switch off 200 Ω or higher Inspection for CANH ground short
      H3-35 (CA2L) - H3-6 (E1) Power switch off 200 Ω or higher Inspection for CANL ground short
      H3-34 (CA2H) - H3-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANH +B short
      H3-35 (CA2L) - H3-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANL +B short
      Table 10. Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)
      Tip:

      It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check V2 Bus Line inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check V2 Bus Line inspection.


  10. Click here

    CHECK FOR SHORT IN V2 BUS LINE (CAN NO. 4 J/C - POWER MANAGEMENT CONTROL ECU)


    1. A003Y1RE31

      Disconnect the power management control ECU main line connector from the CAN No. 4 junction connector.

      Table 11. Text in Illustration
      *a

      Rear view of wire harness connector

      (to CAN No. 4 Junction Connector)
      *b to Power Management Control ECU
    2. A003V8WE31

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      H3-34 (CA2H) - H3-6 (E1) Power switch off 200 Ω or higher Inspection for CANH ground short
      H3-35 (CA2L) - H3-6 (E1) Power switch off 200 Ω or higher Inspection for CANL ground short
      H3-34 (CA2H) - H3-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANH +B short
      H3-35 (CA2L) - H3-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANL +B short
      Table 12. Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)
      Tip:

      It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check V2 Bus Line inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check V2 Bus Line inspection.


  11. Click here

    CHECK FOR SHORT IN V2 BUS LINE (CAN NO. 4 J/C)


    1. Reconnect the power management control ECU main line connector to the CAN No. 4 junction connector.

    2. A003V8WE31

      Connect the probes of an ohmmeter to terminals CANH or CANL and GND or +B (AM22) of the power management control ECU.

      Table 13. Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)
      Tip:

      It is only necessary to perform the inspection for the result (short circuit) that was obtained in the Check V2 Bus Line inspection.

    3. A003X9ZE01

      While observing the resistance value shown on the ohmmeter, disconnect branch line connectors (except H106) from the CAN No. 4 junction connector until the resistance becomes normal (6 kΩ or higher (for +B short) or 200 Ω or higher (for ground short)).

      Table 14. Text in Illustration
      *1 CAN No. 4 Junction Connector - -
      *a Junction Connector B Side *b Junction Connector A Side
      *c Earth Terminal *d

      Front view of wire harness connector

      (to CAN No. 4 Junction Connector)
      Table 15. Junction Connector A Side
      Terminal No. (Symbol) Wiring Color Connected to
      H111-1 (GND) W-B Body ground
      H106-1 (CANH) R Power management control ECU
      H106-2 (CANL) B
      H107-1 (CANH) G Clearance warning ECU assembly
      H107-2 (CANL) B
      H108-1 (CANH) L Driving support ECU assembly
      H108-2 (CANL) B
      H109-1 (CANH) Y Seat belt control ECU
      H109-2 (CANL) B
      Tip:

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

      • 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 CANH and BAT, or the resistance between terminals CANL 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 lines.)

        		 A

        The resistance between terminals CANH and GND, or the resistance between terminals CANL 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 lines.)

        The resistance between terminals CANH and BAT, or the resistance between terminals CANL and BAT 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 lines.)

        		 B

        The resistance between terminals CANH and GND, or the resistance between terminals CANL 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 lines.)

  12. Click here

    CHECK FOR SHORT IN V2 BUS LINE (ECUS)


    1. Reconnect the connector for the bus line that is shorted to +B or GND to the CAN junction connector (the connector that caused the bus line 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 line shorted to +B or GND is connected.

    3. A003V8WE31

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      H3-34 (CA2H) - H3-6 (E1) Power switch off 200 Ω or higher Inspection for CANH ground short
      H3-35 (CA2L) - H3-6 (E1) Power switch off 200 Ω or higher Inspection for CANL ground short
      H3-34 (CA2H) - H3-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANH +B short
      H3-35 (CA2L) - H3-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANL +B short
      Table 16. Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)
      Tip:

      It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check V2 Bus Line inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check V2 Bus Line inspection.


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    REPLACE POWER MANAGEMENT CONTROL ECUClick here

  14. Click here

    REPLACE CAN NO. 4 JUNCTION CONNECTOR

  15. Click here

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 4 J/C - POWER MANAGEMENT CONTROL ECU)

  16. Click here

    REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR BRANCH LINE OR CONNECTOR

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    REPLACE CORRESPONDING ECU OR SENSOR

  18. Click here

    GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC