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

  • Skid control ECU

  • CAN No. 9 junction connector

WIRING DIAGRAM

A01NE4VE02

INSPECTION PROCEDURE

Note


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

  • Turn the power switch off before inspecting CAN bus wires 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.

Tech Tips


  • 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.

PROCEDURE


  1. CHECK POWER MANAGEMENT BUS WIRE


    1. Turn the power switch off.

    2. A01NERPE06
      Text in Illustration
      *1

      Component with harness connector

      (Power Management Control ECU)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition Result
      F98-31 (CA3P) - F98-30 (CA3N) Power switch off 54 to 69 Ω

      Below 54 Ω:

      Short circuit between bus wires

      70 Ω or higher:

      Open circuit in a main bus wires

      F98-31 (CA3P) - F97-6 (E1) Power switch off 200 Ω or higher

      Below 200 Ω:

      CANH ground short

      F98-30 (CA3N) - F97-6 (E1) Power 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
      F98-31 (CA3P) - F98-7 (AM21) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANH +B short

      F98-30 (CA3N) - F98-7 (AM21) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANL +B short

      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      Open circuit in CAN main bus wire C
      Short circuit between bus wires D

      • Ground short

      • +B short

      E

    B
    C
    D
    E
    A
  2. CHECK FOR OPEN IN POWER MANAGEMENT BUS MAIN WIRE (POWER MANAGEMENT CONTROL ECU)


    1. A01NGZSE02
      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 Switch Condition Specified Condition
      F98-31 (CA3P) - F98-30 (CA3N) Power switch off 108 to 132 Ω
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    B
    C
    A
  3. CHECK FOR OPEN IN POWER MANAGEMENT BUS MAIN WIRE (ECM)


    1. Reconnect the power management control ECU connector.

    2. A01NEJ1E05
      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 Switch Condition Specified Condition
      A76-13 (CAN+) - A76-26 (CAN-) Power switch off 108 to 132 Ω

    NG
    OK
  4. CHECK FOR OPEN IN POWER MANAGEMENT BUS MAIN WIRE (CAN NO. 9 J/C MAIN WIRE)


    1. Reconnect the ECM connector.

    2. A01NDFUE59
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 9 Junction Connector)

      *2 to Power Management Control ECU
      *3 to ECM

      Disconnect the CAN No. 9 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F72-2 (CANH) - F72-13 (CANL) Power switch off 108 to 132 Ω
      F72-3 (CANH) - F72-14 (CANL) Power switch off 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (to ECM main wire) B
      NG (to Power management ECU main wire) C

    B
    C
    A
  5. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRE (POWER MANAGEMENT CONTROL ECU)


    1. A01NGZSE02
      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 Switch Condition Specified Condition
      F98-31 (CA3P) - F98-30 (CA3N) Power switch off 108 to 132 Ω
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    B
    C
    A
  6. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRE (ECM)


    1. Reconnect the power management control ECU connector.

    2. A01NEJ1E05
      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 Switch Condition Specified Condition
      A76-13 (CAN+) - A76-26 (CAN-) Power switch off 108 to 132 Ω

    NG
    OK
  7. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRE (CAN NO. 9 J/C MAIN WIRE)


    1. Reconnect the ECM connector.

    2. A01NDFUE59
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 9 Junction Connector)

      *2 to Power Management Control ECU
      *3 to ECM

      Disconnect the CAN No. 9 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F72-2 (CANH) - F72-13 (CANL) Power switch off 108 to 132 Ω
      F72-3 (CANH) - F72-14 (CANL) Power switch off 108 to 132 Ω
      Result
      Result Proceed to
      OK A
      NG (to ECM main wire) B
      NG (to Power management ECU main wire) C

    B
    C
    A
  8. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRE (CAN NO. 9 J/C - AIR CONDITIONING AMPLIFIER)


    1. A01NDFUE60
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 9 Junction Connector)

      *2 to Air Conditioning Amplifier

      Disconnect the air conditioning amplifier connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F72-1 (CANH) - F72-12 (CANL) Power switch off 1 MΩ or higher

    NG
    OK
  9. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRE (CAN NO. 9 J/C - SKID CONTROL ECU)


    1. A01NEQLE11
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 9 Junction Connector)

      *2 to Skid Control ECU

      Disconnect the skid control ECU connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F72-4 (CANH) - F72-15 (CANL) Power switch off 1 MΩ or higher

    NG
    OK
  10. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRE (CAN NO. 9 J/C)


    1. A01NERPE07
      Text in Illustration
      *1

      Component with harness connector

      (Power Management Control ECU)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F98-31 (CA3P) - F98-30 (CA3N) Power switch off 54 to 69 Ω

    NG
    OK
  11. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRE (ECUS)


    1. A01NERPE07
      Text in Illustration
      *1

      Component with harness connector

      (Power Management Control ECU)

      Connect the probes of an ohmmeter to terminals F98-31 (CA3P) and F98-30 (CA3N) of the power management control ECU.

    2. While observing the resistance value shown on the tester, reconnect the each ECU connector until the resistance becomes abnormal (Below 54 Ω).

    3. Replace the ECU that caused the total resistance to drop below 54 Ω when it was reconnected.

      Tech Tips

      If the resistance becomes abnormal when an ECU connector is reconnected, there may be a short in the ECU.


    NEXT
  12. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRE (POWER MANAGEMENT CONTROL ECU)


    1. A01NDSPE03
      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
      F98-31 (CA3P) - F97-6 (E1) Power switch off 200 Ω or higher Inspection for CANH ground short
      F98-30 (CA3N) - F97-6 (E1) Power switch off 200 Ω or higher Inspection for CANL ground short
      F98-31 (CA3P) - F98-7 (AM21) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      F98-30 (CA3N) - F98-7 (AM21) 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 (for LHD) A
      OK (for RHD) B
      NG C

    B
    C
    A
  13. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRE (ECM)


    1. A01NEJ1E08
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      A76-13 (CAN+) - A76-14 (EC) Power switch off 200 Ω or higher Inspection for CANH ground short
      A76-26 (CAN-) - A76-14 (EC) Power switch off 200 Ω or higher Inspection for CANL ground short
      A76-13 (CAN+) - A76-15 (BATT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      A76-26 (CAN-) - A76-15 (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
    OK
  14. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRE (CAN NO. 9 J/C MAIN WIRE)


    1. A01NFVME10
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 9 Junction Connector)

      *2 to Air Conditioning Amplifier
      *3 to Power Management Control ECU
      *4 to ECM
      *5 to Skid Control ECU
      *6 DLC3

      Disconnect the CAN No. 9 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose Connected to
      F72-1 (CANH) - F17-4 (CG) Power switch off 200 Ω or higher Inspection for CANH ground short Air conditioning amplifier
      F72-12 (CANL) - F17-4 (CG) Power switch off 200 Ω or higher Inspection for CANL ground short
      F72-1 (CANH) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      F72-12 (CANL) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short
      F72-2 (CANH) - F17-4 (CG) Power switch off 200 Ω or higher Inspection for CANH ground short Power management control ECU
      F72-13 (CANL) - F17-4 (CG) Power switch off 200 Ω or higher Inspection for CANL ground short
      F72-2 (CANH) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      F72-13 (CANL) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short
      F72-3 (CANH) - F17-4 (CG) Power switch off 200 Ω or higher Inspection for CANH ground short ECM
      F72-14 (CANL) - F17-4 (CG) power switch off 200 Ω or higher Inspection for CANL ground short
      F72-3 (CANH) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      F72-14 (CANL) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short
      F72-4 (CANH) - F17-4 (CG) Power switch off 200 Ω or higher Inspection for CANH ground short Skid control ECU
      F72-15 (CANL) - F17-4 (CG) Power switch off 200 Ω or higher Inspection for CANL ground short
      F72-4 (CANH) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      F72-15 (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 (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 Air conditioning amplifier) B
      NG (to Power management control ECU main wire) C
      NG (to ECM main wire) D
      NG (to Skid control ECU) E

    B
    C
    D
    E
    A
  15. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRE (CAN NO. 9 J/C - A/C ECU)


    1. Disconnect the air conditioning amplifier connector.

    2. A01NCPLE55
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 9 Junction Connector)

      *2 to Air Conditioning Amplifier
      *3 DLC3

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      F72-1 (CANH) - F17-4 (CG) Power switch off 200 Ω or higher Inspection for CANH ground short
      F72-12 (CANL) - F17-4 (CG) Power switch off 200 Ω or higher Inspection for CANL ground short
      F72-1 (CANH) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      F72-12 (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 (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
    OK
  16. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRE (CAN NO. 9 J/C - SKID CONTROL ECU)


    1. Disconnect the skid control ECU connector.

    2. A01NFVME11
      Text in Illustration
      *1

      Front view of wire harness connector

      (to CAN No. 9 Junction Connector)

      *2 to Skid Control ECU
      *3 DLC3

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      F72-4 (CANH) - F17-4 (CG) Power switch off 200 Ω or higher Inspection for CANH ground short
      F72-15 (CANL) - F17-4 (CG) Power switch off 200 Ω or higher Inspection for CANL ground short
      F72-4 (CANH) - F17-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      F72-15 (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 (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
    OK