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DTC U0100: Lost Communication with ECM / PCM "A"; DTC U0129: Lost Communication with Brake System Control Module; DTC U0293: Lost Communication with HV ECU: Procedure

  1. RECONFIRM DTC OUTPUT 
    1. Check if Hybrid Control of the power management control ECU outputs only DTC U0129.

      HINT: 

      If the power management control ECU outputs only DTC U0129, troubleshoot DTC U0129 and check the branch circuit of power management bus.

      Result

      Result Proceed to
      The power management control ECU outputs DTC U0129 and other DTCs.
      (Techstream display: Hybrid Control)      		 A
      The power management control ECU outputs only DTC U0129.
      (Techstream display: Hybrid Control)      		 B

    B → GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC 

    A: Go to next step 

  2. CHECK POWER MANAGEMENT BUS 
    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 L136 Connector Terminals
      GTY328052Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      L136-31 (CA3P) - L136-30 (CA3N) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω Below 54 Ω: Short circuit between bus wires
      70 Ω or higher: Open circuit in a main bus wire
      L136-31 (CA3P) - L136-4 (E12) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANH ground short
      L136-30 (CA3N) - L136-4 (E12) 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
      L136-31 (CA3P) - L136-7 (AM21) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANH +B short
      L136-30 (CA3N) - L136-7 (AM21) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANL +B short

      HINT: 

      • When the values are as specified, clear and recheck for DTCs. When no DTCs are output, check for malfunctions such as damage or improper connection of the relevant connectors.
      • If DTCs are output although the bus circuit is normal and DTCs were cleared, replace the power management control ECU.

      Result

      Result Proceed to
      OK A
      NG (Open circuit in main bus wire) B
      NG (Short circuit between bus wires) C
      • NG (Ground short)
      • NG (+B short)
      		 D

    B → See step   3 

    C → See step   6 

    D → See step   10 

    A → See step   14 

  3. CHECK FOR OPEN IN POWER MANAGEMENT MAIN BUS WIRES (POWER MANAGEMENT CONTROL ECU) 
    1. Disconnect the power management control ECU connector.
      Fig 2: Checking L136 Connector Terminals
      GTY327410Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      L136-31 (CA3P) - L136-30 (CA3N) 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   14 

  4. CHECK FOR OPEN IN POWER MANAGEMENT MAIN BUS WIRES (CAN NO. 5 J/C) 
    1. Reconnect the power management control ECU connector.
    2. Disconnect the CAN No. 5 junction connector.
      Fig 3: Checking L182 Connector Terminals
      GTY326104Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Connected to
      L182-12 (CANH) - L182-1 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Power management control ECU
      L182-15 (CANH) - L182-4 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω ECM
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to CAN No. 5 Junction Connector)
      *b to Power Management Control ECU
      *c to ECM

      Result

      Result Proceed to
      OK A
      NG (Open circuit in power management control ECU CAN main bus wire) B
      NG (Open circuit in ECM CAN main bus wire) C

    B → REPAIR OR REPLACE CAN MAIN BUS WIRE OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - CAN NO. 5 J/C) 

    C → See step   5 

    A → REPLACE CAN NO. 5 JUNCTION CONNECTOR 

  5. CHECK FOR OPEN IN POWER MANAGEMENT MAIN BUS WIRES (ECM - CAN NO. 5 J/C) 
    1. Reconnect the CAN No. 5 junction connector.
    2. Disconnect the ECM connector.
      Fig 4: Checking A57 Connector Terminals
      GTY334652Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A57-12 (CANP) - A57-4 (CANN) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to ECM)

    NG → REPAIR OR REPLACE CAN MAIN BUS WIRE OR CONNECTOR (ECM - CAN NO. 5 J/C) 

    OK → See step   15 

  6. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRES (POWER MANAGEMENT CONTROL ECU) 
    1. Disconnect the power management control ECU connector.
      Fig 5: Checking L136 Connector Terminals
      GTY327410Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      L136-31 (CA3P) - L136-30 (CA3N) 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   7 

    OK → See step   14 

  7. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRES (CAN NO. 5 J/C) 
    1. Reconnect the power management control ECU connector.
    2. Disconnect the CAN No. 5 junction connector.
      Fig 6: Checking L182 Connector Terminals
      GTY333510Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Connected to
      L182-12 (CANH) - L182-1 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Power management control ECU
      L182-14 (CANH) - L182-3 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Brake booster with master cylinder (Skid control ECU)
      L182-15 (CANH) - L182-4 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω ECM
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to CAN No. 5 Junction Connector)
      *b to Power Management Control ECU
      *c to Brake Booster with Master Cylinder (Skid Control ECU)
      *d to ECM

      Result

      Result Proceed to
      OK A
      NG (Short circuit between bus wires in power management control ECU CAN main bus wire) B
      NG (Short circuit between bus lines in ECM CAN main bus wire) C
      NG (Short circuit between bus lines in brake booster with master cylinder assembly (skid control ECU) CAN main bus branch wire) D

    B → REPAIR OR REPLACE CAN MAIN BUS WIRE OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - CAN NO. 5 J/C) 

    C → See step   8 

    D → See step   9 

    A → REPLACE CAN NO. 5 JUNCTION CONNECTOR 

  8. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRES (ECM - CAN NO. 5 J/C) 
    1. Reconnect the CAN No. 5 junction connector.
    2. Disconnect the ECM connector.
      Fig 7: Checking A57 Connector Terminals
      GTY334652Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A57-12 (CANP) - A57-4 (CANN) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to ECM)

    NG → REPAIR OR REPLACE CAN MAIN BUS WIRE OR CONNECTOR (ECM - CAN NO. 5 J/C) 

    OK → See step   15 

  9. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRES (BRAKE BOOSTER WITH MASTER CYLINDER - CAN NO. 5 J/C) 
    1. Reconnect the CAN No. 5 junction connector.
    2. Disconnect the brake booster with master cylinder (skid control ECU) connector.
      Fig 8: Checking A58 Connector Terminals
      GTY339457Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A58-35 (CA2H) - A58-34 (CA2L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to Brake Booster with Master Cylinder (Skid Control ECU))

    NG → REPAIR OR REPLACE CAN MAIN BUS BRANCH WIRE OR CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER - CAN NO. 5 J/C) 

    OK → See step   16 

  10. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRE (CAN NO. 5 J/C) 
    1. Disconnect the CAN No. 5 junction connector.
      Fig 9: Checking L182 & L61 Connector Terminals
      GTY331446Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Purpose Connected to
      L182-12 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Inspection for CANH ground short Power management control ECU
      L182-1 (CANL) - L61-4 (CG) Inspection for CANL ground short
      L182-14 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Inspection for CANH ground short Brake booster with master cylinder (skid control ECU)
      L182-3 (CANL) - L61-4 (CG) Inspection for CANL ground short
      L182-15 (CANH) - L61-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Inspection for CANH ground short ECM
      L182-4 (CANL) - L61-4 (CG) Inspection for CANL ground short
      L182-12 (CANH) - L61-16 (BAT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANH +B short Power management control ECU
      L182-1 (CANL) - L61-16 (BAT) Inspection for CANL +B short
      L182-14 (CANH) - L61-16 (BAT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANH +B short Brake booster with master cylinder (skid control ECU)
      L182-3 (CANL) - L61-16 (BAT) Inspection for CANL +B short
      L182-15 (CANH) - L61-16 (BAT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANH +B short ECM
      L182-4 (CANL) - L61-16 (BAT) Inspection for CANL +B short
      TEXT IN ILLUSTRATION

      *1 DLC3 - -
      *a Front view of wire harness connector
      (to CAN No. 5 Junction Connector)      		 *b to Power Management Control ECU
      *c to Brake Booster with Master Cylinder (Skid Control ECU) *d to ECM

      HINT: 

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

        Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Power Management Bus inspection.

      • If the resistance changes to normal when the connector is disconnected from the ECU, there may be a short in the ECU.

      Result

      Result Proceed to
      OK A
      • NG (Ground short in power management control ECU CAN main bus wire)
      • NG (+B short in power management control ECU CAN main bus wire)
      		 B
      • NG (Ground short in ECM CAN main bus wire)
      • NG (+B short in ECM CAN main bus wire)
      		 C
      • NG (Ground short in brake booster with master cylinder (skid control ECU) CAN main bus branch wire)
      • NG (+B short in brake booster with master cylinder (skid control ECU) CAN main bus branch wire)
      		 D

    B → See step   11 

    C → See step   12 

    D → See step   13 

    A → REPLACE CAN NO. 5 JUNCTION CONNECTOR 

  11. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRE (POWER MANAGEMENT CONTROL ECU - CAN NO. 5 J/C) 
    1. Disconnect the power management control ECU connector.
      Fig 10: Checking L136 Connector Terminals
      GTY328032Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      L136-31 (CA3P) - L136-4 (E12) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      L136-30 (CA3N) - L136-4 (E12)
      L136-31 (CA3P) - L136-7 (AM21) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher
      L136-30 (CA3N) - L136-7 (AM21)
      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 power management bus inspection.
      • Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check power management bus inspection.

    NG → REPAIR OR REPLACE CAN MAIN BUS WIRE OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - CAN NO. 5 J/C) 

    OK → See step   14 

  12. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRE (ECM - CAN NO. 5 J/C) 
    1. Disconnect the ECM connector.
      Fig 11: Checking A57 & D28 Connector Terminals
      GTY338790Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Purpose
      A57-12 (CANP) - D28-104 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANH ground short
      A57-4 (CANN) - D28-104 (E1) Below 200 Ω: CANL ground short
      A57-12 (CANP) - A57-20 (BATT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANH +B short
      A57-4 (CANN) - A57-20 (BATT) Below 6 kΩ: CANL +B short
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to ECM)

      HINT: 

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

        Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Power Management Bus inspection.

      • If the resistance changes to normal when the connector is disconnected from the ECU, there may be a short in the ECU.

    NG → REPAIR OR REPLACE CAN MAIN BUS WIRE OR CONNECTOR (ECM - CAN NO. 5 J/C) 

    OK → See step   15 

  13. CHECK FOR SHORT IN POWER MANAGEMENT BUS WIRE (BRAKE BOOSTER WITH MASTER CYLINDER - CAN NO. 5 J/C) 
    1. Disconnect the brake booster with master cylinder (skid control ECU) connector.
      Fig 12: Checking A58 Connector Terminals
      GTY339459Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Purpose
      A58-35 (CA2H) - A58-28 (GND) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANH ground short
      A58-34 (CA2L) - A58-28 (GND) Below 200 Ω: CANL ground short
      A58-35 (CA2H) - A58-15 (BS) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANH +B short
      A58-34 (CA2L) - A58-15 (BS) Below 6 kΩ: CANL +B short
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to Brake Booster with Master Cylinder (Skid 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 Power Management Bus inspection.

        Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Power Management Bus inspection.

      • If the resistance changes to normal when the connector is disconnected from the ECU, there may be a short in the ECU.

    NG → REPAIR OR REPLACE CAN MAIN BUS BRANCH WIRE OR CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER - CAN NO. 5 J/C) 

    OK → See step   16 

  14. REPLACE POWER MANAGEMENT CONTROL ECU. Refer to  REMOVAL 
  15. REPLACE ECM. Refer to  REMOVAL 
  16. REPLACE BRAKE BOOSTER WITH MASTER CYLINDER. Refer to  REMOVAL 
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