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DTC U1002: Lost Communication with Gateway Module (Power Management1): Procedure

  1. CHECK V2 BUS WIRE 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Measure the resistance according to the value(s) in the table below.
      Fig 1: Checking L135 Connector Terminals
      GTY341872Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Switch Condition Specified Condition Result
      L135-34 (CA2H) - L135-35 (CA2L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω Below 54 Ω:
      Short circuit between bus lines
      70 Ω or higher:
      Open circuit in a main bus line
      L135-34 (CA2H) - L135-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω:
      CANH ground short
      L135-35 (CA2L) - L135-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω:
      CANL ground short
      TEXT IN ILLUSTRATION

      *a Component with harness connected
      (Power Management Control ECU)
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      L135-34 (CA2H) - L135-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ:
      CANH +B short
      L135-35 (CA2L) - L135-1 (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 wire B
      Short circuit between bus wires C
      • Ground short
      • +B short
      		 D

    B → See step   3 

    C → See step   6 

    D → See step   11 

    A: Go to next step 

  2. CHECK DTC OUTPUT 
    1. Clear the DTC.
    2. Turn the power switch off.
    3. Turn the power switch on (IG), recheck for the DTC.

      Result

      Result Proceed to
      U1002 is output from power management control ECU
      (Techstream display/ PM1 Gateway)      		 A
      Other DTC is output B

    B → GO TO CIRCUITS INDICATED BY OUTPUT DTCS 

    A → See step   16 

  3. CHECK FOR OPEN IN V2 MAIN BUS WIRE (POWER MANAGEMENT CONTROL ECU MAIN WIRE) 
    1. Disconnect the power management control ECU connector.
    2. Measure the resistance according to the value(s) in the table below.
      Fig 2: Checking L135 Connector Terminals
      GTY342090Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      L135-34 (CA2H) - L135-35 (CA2L) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to Power Management Control ECU)

    NG → See step   4 

    OK → See step   16 

  4. CHECK FOR OPEN IN V2 MAIN BUS WIRE (CAN NO. 3 J/C) 
    1. Reconnect the power management control ECU connector.
    2. Disconnect the wire harness connector from the CAN No. 3 junction connector.
      Fig 3: Checking L183 Connector Terminals
      GTY333511Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to CAN No. 3 Junction Connector)
      *b to Power Management Control ECU
      *c to 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
      L183-2 (CANH) - L183-13 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Power management control ECU
      L183-3 (CANH) - L183-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω CAN No. 4 junction connector

      Result

      Result Proceed to
      OK A
      NG (to Power management control ECU) B
      NG (to CAN No. 4 junction connector) C

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

    C → See step   5 

    A → REPLACE CAN NO. 3 JUNCTION CONNECTOR 

  5. CHECK FOR OPEN IN V2 MAIN BUS WIRE (CAN NO. 4 J/C) 
    1. Reconnect the wire harness connector to the CAN No. 3 junction connector.
    2. Disconnect the wire harness connector (L97) from the CAN No. 4 junction connector.
      Fig 4: Checking L97 Connector Terminals
      GTY328275Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to CAN No. 4 Junction Connector)
      *b to CAN No. 3 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
      L97-1 (CANH) - L97-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω CAN No. 3 junction connector

    NG → REPAIR OR REPLACE CAN MAIN BUS WIRE OR CONNECTOR (CAN NO. 4 J/C - CAN NO. 3 J/C) 

    OK → REPLACE CAN NO. 4 JUNCTION CONNECTOR 

  6. CHECK FOR SHORT IN V2 BUS WIRE (POWER MANAGEMENT CONTROL ECU) 
    1. Disconnect the power management control ECU connector.
      Fig 5: Checking L135 Connector Terminals
      GTY342090Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to Power Management Control ECU)
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      L135-34 (CA2H) - L135-35 (CA2L) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    NG → See step   7 

    OK → See step   16 

  7. CHECK FOR SHORT IN V2 BUS WIRE (CAN NO. 3 J/C - POWER MANAGEMENT CONTROL ECU) 
    1. Reconnect the power management control ECU connector.
    2. Disconnect the wire harness connector from the CAN No. 3 junction connector.
      Fig 6: Checking L183 Connector Terminals
      GTY333514Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to CAN No. 3 Junction Connector)
      *b Transmission Control ECU Assembly
      *c to Power Management Control ECU
      *d to 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
      L183-1 (CANH) - L183-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Transmission control ECU assembly
      L183-2 (CANH) - L183-13 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Power management control ECU
      L183-3 (CANH) - L183-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω CAN No. 4 junction connector

      Result

      Result Proceed to
      OK A
      NG (Short circuit between bus wires in power management control ECU CAN main bus wire) B
      NG (to CAN No. 4 junction connector) C
      NG (Short circuit between bus wires in transmission control ECU assembly CAN branch wire) D

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

    C → See step   8 

    D → See step   10 

    A → See step   16 

  8. CHECK FOR SHORT IN V2 BUS WIRE (CAN NO. 4 J/C - CAN NO. 3 J/C) 
    1. Reconnect the wire harness connector to the CAN No. 3 junction connector.
    2. Disconnect the wire harness connector (L97) from the CAN No. 4 junction connector.
      Fig 7: Checking L97 Connector Terminals
      GTY328275Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to CAN No. 4 Junction Connector)
      *b to CAN No. 3 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
      L97-1 (CANH) - L97-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω CAN No. 3 junction connector

    NG → REPAIR OR REPLACE CAN MAIN BUS WIRE OR CONNECTOR (CAN NO. 4 J/C - CAN NO. 3 J/C) 

    OK → REPLACE CAN NO. 4 JUNCTION CONNECTOR 

  9. CHECK FOR SHORT IN V2 BUS WIRE (CAN NO. 4 J/C) 
    1. Reconnect the power management control ECU main wire connector to the CAN No. 4 junction connector.
    2. Connect the probes of an ohmmeter to terminals 34 (CA2H) and 35 (CA2L) of the power management control ECU.
      Fig 8: Checking L135 Connector Terminals
      GTY324387Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Component with harness connector
      (Power Management Control ECU)
    3. While observing the resistance value shown on the ohmmeter, disconnect branch wire connectors (except CC) from the CAN No. 4 junction connector until the resistance becomes normal (between 54 and 69 Ω).
      Fig 9: Checking CAN No. 4 Junction Connector Terminals
      GTY332898Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a CAN No. 4 Junction Connector *b Junction Connector B Side
      *c Junction Connector A Side *d Earth Terminal
      *e Front view of wire harness connector
      (to CAN No. 4 Junction Connector)      		 - -
      Terminal No. (Symbol) Wiring Color Connected to
      L98-1 (CANH) LG Seat belt control ECU
      L98-2 (CANL) L
      L164-1 (CANH) B Driving support ECU
      L164-2 (CANL) W
      L97-1 (CANH) V CAN No. 3 junction connector
      L97-2 (CANL) W
      L166-1 (CANH) Y Air conditioning amplifier assembly
      L166-2 (CANL) BR
      L165-1 (CANH) R Center airbag sensor assembly
      L165-2 (CANL) G

      HINT: 

      • 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 connectors are 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 → See step   10 

    A → REPLACE CAN NO. 4 JUNCTION CONNECTOR 

  10. CHECK FOR SHORT IN V2 BUS WIRE (ECUS) 
    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. Measure the resistance according to the value(s) in the table below.
      Fig 10: Checking L135 Connector Terminals
      GTY324387Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Switch Condition Specified Condition
      L135-34 (CA2H) - L135-35 (CA2L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω
      TEXT IN ILLUSTRATION

      *a Component with harness connector
      (Power Management Control ECU)

      HINT: 

      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 CORRESPONDING ECU OR SENSOR BRANCH WIRE OR CONNECTOR 

    OK → REPLACE CORRESPONDING ECU OR SENSOR 

  11. CHECK FOR SHORT IN V2 BUS WIRE (POWER MANAGEMENT CONTROL ECU) 
    1. Disconnect the power management control ECU connector.
      Fig 11: Checking L135 Connector Terminals
      GTY342091Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to Power Management Control ECU)
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Purpose
      L135-34 (CA2H) - L135-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Inspection for CANH ground short
      L135-35 (CA2L) - L135-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Inspection for CANL ground short
      L135-34 (CA2H) - L135-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANH +B short
      L135-35 (CA2L) - L135-1 (AM22) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANL +B short

      HINT: 

      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 Wire inspection.

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

    NG → See step   12 

    OK → See step   16 

  12. CHECK FOR SHORT IN V2 BUS WIRE (CAN NO. 3 J/C - POWER MANAGEMENT CONTROL ECU) 
    1. Disconnect the wire harness connector from the CAN No. 3 junction connector.
      Fig 12: Checking L183 Connector Terminals
      GTY333511Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to CAN No. 3 Junction Connector)
      *b to Power Management Control ECU
      *c to CAN No. 4 Junction Connector
    2. Measure the resistance according to the value(s) in the table below.
      Fig 13: Checking L135 Connector Terminals
      GTY342091Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Condition Specified Condition Purpose
      L135-34 (CA2H) - L135-6 (E1) Power switch off 200 Ω or higher Inspection for CANH ground short
      L135-35 (CA2L) - L135-6 (E1) Power switch off 200 Ω or higher Inspection for CANL ground short
      L135-34 (CA2H) - L135-1 (AM22) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      L135-35 (CA2L) - L135-1 (AM22) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to Power Management Control ECU)

      Result

      Result Proceed to
      OK A
      NG (to Power management control ECU) B
      NG (to CAN No. 4 junction connector main bus wire) C
      NG (to Transmission control ECU assembly) D

      HINT: 

      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 Wire inspection.

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

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

    C → See step   13 

    D → See step   15 

    A → REPLACE CAN NO. 3 JUNCTION CONNECTOR 

  13. CHECK FOR SHORT IN V2 BUS WIRE (CAN NO. 4 J/C - CAN NO. 3 J/C) 
    1. Reconnect the wire harness connector to the CAN No. 3 junction connector.
    2. Disconnect the wire harness connector (L97) from the CAN No. 4 junction connector.
      Fig 14: Checking L97 Connector Terminals
      GTY328275Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to CAN No. 4 Junction Connector)
      *b to CAN No. 3 Junction Connector
    3. Measure the resistance according to the value(s) in the table below.
      Fig 15: Checking L135 Connector Terminals
      GTY342091Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Condition Specified Condition Purpose
      L135-34 (CA2H) - L135-6 (E1) Power switch off 200 Ω or higher Inspection for CANH ground short
      L135-35 (CA2L) - L135-6 (E1) Power switch off 200 Ω or higher Inspection for CANL ground short
      L135-34 (CA2H) - L135-1 (AM22) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      L135-35 (CA2L) - L135-1 (AM22) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to Power Management Control ECU)

      HINT: 

      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 Wire inspection.

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

    NG → REPAIR OR REPLACE CAN MAIN BUS WIRE OR CONNECTOR (CAN NO. 4 J/C - CAN NO. 3 J/C) 

    OK: Go to next step 

  14. CHECK FOR SHORT IN V2 BUS WIRE (CAN NO. 4 J/C) 
    1. Reconnect the wire harness connector (L97) to the CAN No. 4 junction connector.
    2. Connect the probes of an ohmmeter to terminals CANH or CANL and GND or +B (AM22) of the power management control ECU.
      Fig 16: Checking L135 Connector Terminals
      GTY342091Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to Power Management Control ECU)

      HINT: 

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

    3. While observing the resistance value shown on the ohmmeter, disconnect branch wire connector (except CC) 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)).
      Fig 17: Checking CAN No. 4 Junction Connector Terminals
      GTY332898Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a CAN No. 4 Junction Connector *b Junction Connector B Side
      *c Junction Connector A Side *d Earth Terminal
      *e Front view of wire harness connector
      (to CAN No. 4 Junction Connector)      		 - -
      Terminal No. (Symbol) Wiring Color Connected to
      L98-1 (CANH) LG Seat belt control ECU
      L98-2 (CANL) L
      L164-1 (CANH) B Driving support ECU
      L164-2 (CANL) W
      L97-1 (CANH) V CAN No. 3 junction connector
      L97-2 (CANL) W
      L166-1 (CANH) Y Air conditioning amplifier assembly
      L166-2 (CANL) BR
      L165-1 (CANH) R Center airbag sensor assembly
      L165-2 (CANL) G

      HINT: 

      • 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 BAT, or the resistance between terminals 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 terminals 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 BAT, or the resistance between terminals CANN 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 wires.)        		 B
        The resistance between terminals CANP and GND, or the resistance between terminals 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 → See step   15 

    A → REPLACE CAN NO. 4 JUNCTION CONNECTOR 

  15. CHECK FOR SHORT IN V2 BUS WIRE (ECUS) 
    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. Measure the resistance according to the value(s) in the table below.
      Fig 18: Checking L135 Connector Terminals
      GTY342091Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Condition Specified Condition Purpose
      L135-34 (CA2H) - L135-6 (E1) Power switch off 200 Ω or higher Inspection for CANH ground short
      L135-35 (CA2L) - L135-6 (E1) Power switch off 200 Ω or higher Inspection for CANL ground short
      L135-34 (CA2H) - L135-1 (AM22) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      L135-35 (CA2L) - L135-1 (AM22) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to Power Management Control ECU)

      HINT: 

      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 Wire inspection.

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

    NG → REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR BRANCH WIRE OR CONNECTOR 

    OK → REPLACE CORRESPONDING ECU OR SENSOR 

  16. REPLACE POWER MANAGEMENT CONTROL ECU. Refer to  REMOVAL 
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