CAN COMMUNICATION SYSTEM, Diagnostic DTC:U1002

DTC Code DTC Name
U1002 Lost Communication with Gateway Module (Power Management2)

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 power management bus.

  • Open or short in power management bus main wire or connector

  • Open or short in power management bus branch wire or connector

  • Power management control ECU

  • ECM

  • Air conditioning amplifier assembly

  • CAN No. 1 junction connector

WIRING DIAGRAM

A01EL9RE02

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 BUS WIRE


    1. Turn the ignition switch off.

    2. A01EKD4E03
      Text in Illustration
      *1

      Component with harness connected

      (Power Management Control ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      D43-12 (CA3P) - D43-11 (CA3N) Ignition switch off 54 to 69 Ω

      Below 54 Ω:

      Short circuit between bus wires

      70 Ω or higher:

      Open circuit in a main bus wire
      D43-12 (CA3P) - D43-6 (GND) Ignition switch off 200 Ω or higher

      Below 200 Ω:

      CANH ground short
      D43-11 (CA3N) - D43-6 (GND) 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
      D43-12 (CA3P) - D43-1 (AM22) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANH +B short
      D43-11 (CA3N) - D43-1 (AM22) 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 WIRE (POWER MANAGEMENT CONTROL ECU) Click here

    C

    CHECK FOR SHORT IN CAN BUS WIRE (POWER MANAGEMENT CONTROL ECU) Click here

    D

    CHECK FOR SHORT IN CAN BUS WIRES (POWER MANAGEMENT CONTROL ECU) Click here

    A

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

  2. CHECK FOR OPEN IN CAN BUS WIRE (POWER MANAGEMENT CONTROL ECU)


    1. A01ELA6E37
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to Power Management Control ECU)

      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
      D43-12 (CA3P) - D43-11 (CA3N) Ignition switch off 108 to 132 Ω

    NG

    CHECK FOR OPEN IN CAN BUS WIRE (ECM) Click here

    OK

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

  3. CHECK FOR OPEN IN CAN BUS WIRE (ECM)


    1. Reconnect the power management control ECU connector.

    2. A01EMIIE77
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A49-12 (CANP) - A49-4 (CANN) Ignition switch off 108 to 132 Ω

    NG

    CHECK FOR OPEN IN CAN BUS WIRE (CAN NO. 1 J/C MAIN WIRE) Click here

    OK

    REPLACE ECM Click here

  4. CHECK FOR OPEN IN CAN BUS WIRE (CAN NO. 1 J/C MAIN WIRE)


    1. Reconnect the ECM connector.

    2. A01EMC6E02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *2 to Power Management Control ECU
      *3 to ECM

      Disconnect the CAN No. 1 junction connectors (A44 and D56).

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D56-4 (CANH) - D56-15 (CANL) Ignition switch off 108 to 132 Ω
      A44-8 (CANH) - A44-19 (CANL) Ignition switch off 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (to ECM main wire) B
      NG (to Power management control ECU main wire) C

    B

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 J/C - ECM)

    C

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 J/C - POWER MANAGEMENT CONTROL ECU)

    A

    REPLACE CAN NO. 1 J/C

  5. CHECK FOR SHORT IN CAN BUS WIRE (POWER MANAGEMENT CONTROL ECU)


    1. A01ELA6E37
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to Power Management Control ECU)

      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
      D43-12 (CA3P) - D43-11 (CA3N) Ignition switch off 108 to 132 Ω

    NG

    CHECK FOR SHORT IN CAN BUS WIRES (ECM) Click here

    OK

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

  6. CHECK FOR SHORT IN CAN BUS WIRES (ECM)


    1. Reconnect the power management control ECU connector.

    2. A01EMIIE78
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A49-12 (CANP) - A49-4 (CANN) Ignition switch off 108 to 132 Ω

    NG

    CHECK FOR SHORT IN CAN BUS MAIN WIRE (CAN NO. 1 J/C MAIN WIRE) Click here

    OK

    REPLACE ECM Click here

  7. CHECK FOR SHORT IN CAN BUS MAIN WIRE (CAN NO. 1 J/C MAIN WIRE)


    1. Reconnect the ECM connector.

    2. A01EMC6E02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *2 to Power Management Control ECU
      *3 to ECM
      *4 to Air Conditioning Amplifier Assembly

      Disconnect the CAN No. 1 junction connectors (A44 and D56).

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D56-4 (CANH) - D56-15 (CANL) Ignition switch off 108 to 132 Ω
      D56-3 (CANH) - D56-14 (CANL) Ignition switch off 200 Ω or higher
      A44-8 (CANH) - A44-19 (CANL) Ignition switch off 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (to ECM main wire) B
      NG (to Power management control ECU main wire) C
      NG (to Air conditioning amplifier assembly branch wire) D

    B

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 J/C - ECM)

    C

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 J/C - POWER MANAGEMENT CONTROL ECU)

    D

    CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 1 J/C - AIR CONDITIONING AMPLIFIER ASSEMBLY) Click here

    A

    REPLACE CAN NO. 1 J/C

  8. CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 1 J/C - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. Disconnect the air conditioning amplifier assembly connector.

    2. A01EL64E16
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *2 to Air Conditioning Amplifier Assembly

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D56-3 (CANH) - D56-14 (CANL) Ignition switch off 1 MΩ or higher

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 1 J/C - AIR CONDITIONING AMPLIFIER ASSEMBLY)

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

  9. CHECK FOR SHORT IN CAN BUS WIRES (POWER MANAGEMENT CONTROL ECU)


    1. A01ELA6E16
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to Power Management Control ECU)

      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
      D43-12 (CA3P) - D43-6 (GND) Ignition switch off 200 Ω or higher Inspection for CANH ground short
      D43-11 (CA3N) - D43-6 (GND) Ignition switch off 200 Ω or higher Inspection for CANL ground short
      D43-12 (CA3P) - D43-1 (AM22) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      D43-11 (CA3N) - D43-1 (AM22) 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 Bus Wire inspection.

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


    NG

    CHECK FOR SHORT IN CAN BUS WIRES (ECM) Click here

    OK

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

  10. CHECK FOR SHORT IN CAN BUS WIRES (ECM)


    1. Disconnect the ECM connectors.

      A01ELWDE08
      Text in Illustration
      *1 Front view of wire harness connector (to ECM)

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      A49-12 (CANP) - B58-104 (E1) Ignition switch off 200 Ω or higher Inspection for CANH ground short
      A49-4 (CANN) - B58-104 (E1) Ignition switch off 200 Ω or higher Inspection for CANL ground short
      A49-12 (CANP) - A49-20 (BATT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      A49-4 (CANN) - A49-20 (BATT) 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 Bus Wire inspection.

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


    NG

    CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 1 J/C MAIN WIRE) Click here

    OK

    REPLACE ECM Click here

  11. CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 1 J/C MAIN WIRE)


    1. A01EIMNE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *2 to Power Management Control ECU
      *3 to ECM
      *4 to Air Conditioning Amplifier Assembly
      *5 DLC3

      Disconnect the CAN No. 1 junction connectors (A44 and D56).

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose Connected to
      D56-4 (CANH) - D1-4 (CG) Ignition switch off 200 Ω or higher Inspection for CANH ground short Power management control ECU
      D56-15 (CANL) - D1-4 (CG) Ignition switch off 200 Ω or higher Inspection for CANL ground short
      D56-4 (CANH) - D1-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      D56-15 (CANL) - D1-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short
      D56-3 (CANH) - D1-4 (CG) Ignition switch off 200 Ω or higher Inspection for CANH ground short Air conditioning amplifier assembly
      D56-14 (CANL) - D1-4 (CG) Ignition switch off 200 Ω or higher Inspection for CANL ground short
      D56-3 (CANH) - D1-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      D56-14 (CANL) - D1-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short
      A44-8 (CANH) - D1-4 (CG) Ignition switch off 200 Ω or higher Inspection for CANH ground short ECM
      A44-19 (CANL) - D1-4 (CG) Ignition switch off 200 Ω or higher Inspection for CANL ground short
      A44-8 (CANH) - D1-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      A44-19 (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 Bus Wire inspection.

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

      Result
      Result Proceed to
      OK A
      NG (to ECM main wire) B
      NG (to Power management control ECU main wire) C
      NG (to Air conditioning amplifier assembly branch wire) D

    B

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 J/C - ECM)

    C

    REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN NO. 1 J/C - POWER MANAGEMENT CONTROL ECU)

    D

    CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 1 J/C - AIR CONDITIONING AMPLIFIER ASSEMBLY) Click here

    A

    REPLACE CAN NO. 1 J/C

  12. CHECK FOR SHORT IN CAN BUS WIRES (CAN NO. 1 J/C - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. Disconnect the air conditioning amplifier assembly connector.

    2. A01EKTLE44
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 1 Junction Connector)
      *2 to Air Conditioning Amplifier Assembly
      *3 DLC3

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      D56-3 (CANH) - D1-4 (CG) Ignition switch off 200 Ω or higher Inspection for CANH ground short
      D56-14 (CANL) - D1-4 (CG) Ignition switch off 200 Ω or higher Inspection for CANL ground short
      D56-3 (CANH) - D1-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      D56-14 (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 Bus Wire inspection.

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


    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (CAN NO. 1 J/C - AIR CONDITIONING AMPLIFIER ASSEMBLY)

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here