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HYBRID BATTERY SYSTEM, Diagnostic DTC:U029A-123

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DTC Code DTC Name
U029A-123 Lost Communication with Hybrid Battery Pack Sensor Module
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DESCRIPTION

The battery smart unit detects the HV battery conditions (voltage, current, and temperature) and battery cooling fan voltage, and sends the detected signals to the power management control ECU via serial communication.

DTC No. INF Code DTC Detection Condition Trouble Area
U029A 123 Problem in serial communication between the battery smart unit and power management control ECU (1 trip detection)

  • Wire harness or connector

  • Power management control ECU

  • Battery smart unit
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WIRING DIAGRAM

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CAUTION / NOTICE / HINT

CAUTION:

  • Before inspecting the high-voltage system, take safety precautions to prevent electrical shocks, such as wearing insulated gloves and removing the service plug grip. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.

  • After removing the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work (Click here).

    Tip:

    At least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

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).

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PROCEDURE


  1. Click here

    CHECK DTC OUTPUT (HYBRID CONTROL)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

    4. Check for DTCs (Click here).

      Result
      Result Proceed to
      Only U029A-123 is output. A
      DTCs except U029A-123 are also output. B

    5. Turn the power switch off.

    6. Disconnect the GTS from the DLC3.


  2. Click here

    CHECK BATTERY SMART UNIT (IGCT VOLTAGE)

    CAUTION:

    Be sure to wear insulated gloves.


    1. Check that the service plug grip is not installed.

      Note:

      After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

    2. Remove the rear seat side garnish LH (Click here).

    3. Connect the cable to the negative (-) auxiliary battery terminal.

    4. Turn the power switch on (IG).

    5. A0006YLE04

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      P10-3 (IGCT) - P10-6 (GND) Power switch on (IG) 11 to 14 V
      Table 1. Text in Illustration
      *a

      Component with harness connected

      (Battery Smart Unit)
      Note:

      Turning the power switch on (IG) with the service grip removed causes other DTCs to be stored. Clear the DTCs after performing this inspection.

      Tip:

      As there might be an intermittent malfunction in the battery smart unit power source circuit, inspect the following even if the measured voltage is as specified:


      • Installation condition of fuse(s) (before removing fuse(s)) (IGCT circuit)

      • Fuse condition (before and after removing fuse(s)) (IGCT circuit)

      • Connection condition of connectors (IGCT circuit)

      • Wire harness condition (IGCT circuit)

      • Wire harness condition (GND circuit)

    6. Turn the power switch off.

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

    8. Install the rear seat side garnish LH.


    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY SMART UNIT POWER SOURCE CIRCUIT)

  3. Click here

    CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - BATTERY SMART UNIT)

    CAUTION:

    Be sure to wear insulated gloves.


    1. Check that the service plug grip is not installed.

      Note:

      After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

    2. Disconnect the H1 power management control ECU connector (Click here).

    3. Remove the rear seat side garnish LH (Click here).

    4. Disconnect the P10 battery smart unit connector.

    5. A0008RDE01
      A0007EOE01

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H1-32 (BTH+) - P10-1 (BTH+) Power switch off Below 1 Ω
      H1-33 (BTH-) - P10-4 (BTH-) Power switch off Below 1 Ω
      P10-1 (BTH+) - P10-6 (GND) and Body ground Power switch off 10 kΩ or higher
      P10-4 (BTH-) - P10-6 (GND) and Body ground Power switch off 10 kΩ or higher
      Table 2. Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)
      *b

      Rear view of wire harness connector

      (to Battery Smart Unit)
    6. A0005E3E06

      Remove the PM IGCT fuse from the No. 2 engine room relay block.

      Table 3. Text in Illustration
      *1 No. 2 Engine Room Relay Block
      *2 PM IGCT fuse
    7. A0004BTE02

      Remove the AM2 fuse and ECU-IG2 No. 3 fuse from the engine room relay block and junction block assembly.

      Table 4. Text in Illustration
      *1 Engine Room Relay Block and Junction Block Assembly
      *2 AM2 fuse
      *3 ECU-IG2 No. 3 fuse

    8. Disconnect the A31, A33 and H2 power management control ECU connectors.

    9. A0003F6E02

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

      Table 5. Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      H1-32 (BTH+) - H2-7 (AM21) Power switch off 10 kΩ or higher
      H1-32 (BTH+) - H1-1 (AM22) Power switch off 10 kΩ or higher
      H1-32 (BTH+) - A31-2 (+B2) Power switch off 10 kΩ or higher
      H1-32 (BTH+) - A33-5 (+B1) Power switch off 10 kΩ or higher
      H1-32 (BTH+) - A33-6 (MREL) Power switch off 10 kΩ or higher
      H1-32 (BTH+) - A33-1 (IG2) Power switch off 10 kΩ or higher
      H1-32 (BTH+) - H2-1 (ACCD) Power switch off 10 kΩ or higher
      H1-32 (BTH+) H2-2 (IG1D) Power switch off 10 kΩ or higher
      H1-32 (BTH+) - A33-2 (IG2D) Power switch off 10 kΩ or higher
      H1-32 (BTH+) - H1-14 (SPDI) Power switch off 10 kΩ or higher
      H1-32 (BTH+) - A31-16 (GI) Power switch off 10 kΩ or higher
      H1-33 (BTH-) - H2-7 (AM21) Power switch off 10 kΩ or higher
      H1-33 (BTH-) - H1-1 (AM22) Power switch off 10 kΩ or higher
      H1-33 (BTH-) - A31-2 (+B2) Power switch off 10 kΩ or higher
      H1-33 (BTH-) - A33-5 (+B1) Power switch off 10 kΩ or higher
      H1-33 (BTH-) - A33-6 (MREL) Power switch off 10 kΩ or higher
      H1-33 (BTH-) - A33-1 (IG2) Power switch off 10 kΩ or higher
      H1-33 (BTH-) - H2-1 (ACCD) Power switch off 10 kΩ or higher
      H1-33 (BTH-) - H2-2 (IG1D) Power switch off 10 kΩ or higher
      H1-33 (BTH-) - A33-2 (IG2D) Power switch off 10 kΩ or higher
      H1-33 (BTH-) - H1-14 (SPDI) Power switch off 10 kΩ or higher
      H1-33 (BTH-) - A31-16 (GI) Power switch off 10 kΩ or higher
      Note:

      When taking a measurement with a tester, do not apply excessive force to the tester probe to avoid damaging the holder.

    10. Install the AM2 fuse and ECU-IG2 No. 3 fuse to the engine room relay block and junction block assembly.

    11. Install the PM IGCT fuse to the No. 2 engine room relay block.

    12. Reconnect the P10 battery smart unit connector.

    13. Install the rear seat side garnish LH.

    14. Reconnect the A31, A33, H1 and H2 power management control ECU connectors.


    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - BATTERY SMART UNIT)

  4. Click here

    CHECK POWER MANAGEMENT CONTROL ECU

    CAUTION:

    Be sure to wear insulated gloves.


    1. Check that the service plug grip is not installed.

      Note:

      After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

    2. Remove the rear seat side garnish LH (Click here).

    3. Disconnect the P10 battery smart unit connector.

    4. Connect the cable to the negative (-) auxiliary battery terminal.

    5. Turn the power switch on (IG).

    6. A0008PNE03

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      P10-1 (BTH+) - P10-6 (GND) Power switch on (IG) 2.3 to 2.7 V
      P10-4 (BTH-) - P10-6 (GND) Power switch on (IG) 2.3 to 2.7 V
      Table 6. Text in Illustration
      *a

      Rear view of wire harness connector

      (to Battery Smart Unit)
      Note:

      Turning the power switch on (IG) with the battery smart unit connector and power management control ECU connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

    7. Turn the power switch off.

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

    9. A0007D4E03

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      P10-1 (BTH+) - P10-4 (BTH-) Power switch off 4.4 to 5.4 kΩ
      Table 7. Text in Illustration
      *a

      Rear view of wire harness connector

      (to Battery Smart Unit)
      Tip:

      Resistance becomes 2.0 kΩ or less when there is a short circuit in the power management control ECU.

    10. Reconnect the P10 battery smart unit connector.

    11. Install the rear seat side garnish LH.