HYBRID BATTERY SYSTEM, Diagnostic DTC:U029A-123

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

DESCRIPTION

The battery smart unit detects the HV battery conditions (voltage, current, and temperature) and battery cooling blower assembly 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

WIRING DIAGRAM

A01V1GDE03

CAUTION / NOTICE / HINT

CAUTION:


  • Before inspecting the high-voltage system or disconnecting the low voltage connector of the inverter with converter assembly, turn the ignition switch off and take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. 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.

    Tech Tips

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

Note

After turning the ignition 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.

PROCEDURE


  1. CHECK FOR DTCS (HYBRID CONTROL)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to 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 other than U029A-123 are also output. B

    5. Turn the ignition switch off.


    B

    GO TO DTC CHART (HYBRID BATTERY SYSTEM) Click here

    A

  2. 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 ignition switch to ON (READY), unless instructed by the repair manual because this may cause a malfunction.

    2. Disconnect the power management control ECU connector.

    3. Remove the No. 1 hybrid battery exhaust duct Click here.

    4. Disconnect the battery smart unit connector.

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

      A01UZK9E01
      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F55-32 (BTH+) - K32-1 (BTH+) Ignition switch off Below 1 Ω
      F55-33 (BTH-) - K32-4 (BTH-) Ignition switch off Below 1 Ω
      K32-1 (BTH+) - K32-6 (GND) and Body ground Ignition switch off 10 kΩ or higher
      K32-4 (BTH-) - K32-6 (GND) and Body ground Ignition switch off 10 kΩ or higher
      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. A01V0A5E02
      Text in Illustration
      *1 No. 2 Engine Room Relay Block
      *2 IG2 No. 2 fuse
      *3 IGCT No. 2 fuse
      *4 AM2 fuse

      Remove the IG2 No. 2 fuse, IGCT No. 2 fuse, AM2 fuse from the No. 2 engine room relay block. (w/ power switch)

    7. A01UXK4E02
      Text in Illustration
      *1 No. 2 Engine Room Relay Block
      *2 IG2 No. 2 fuse
      *3 IGCT No. 2 fuse
      *4 ECU-B No. 2 fuse

      Remove the IG2 No. 2 fuse, IGCT No. 2 fuse, ECU-B No. 2 fuse from the No. 2 engine room relay block. (w/o power switch)

    8. Disconnect the power management control ECU connectors.

    9. Measure the resistance according to the value(s) in the table below. (w/ power switch)

      A01UXO6E02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      		 - -
      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F55-32 (BTH+) - F56-7 (AM21) Ignition switch off 10 kΩ or higher
      F55-32 (BTH+) - F55-1 (AM22) Ignition switch off 10 kΩ or higher
      F55-32 (BTH+) - A26-2 (+B2) Ignition switch off 10 kΩ or higher
      F55-32 (BTH+) - A27-5 (+B1) Ignition switch off 10 kΩ or higher
      F55-32 (BTH+) - A27-6 (MREL) Ignition switch off 10 kΩ or higher
      F55-32 (BTH+) - A27-1 (IG2) Ignition switch off 10 kΩ or higher
      F55-32 (BTH+) - F56-1 (ACCD) Ignition switch off 10 kΩ or higher
      F55-32 (BTH+) F56-2 (IG1D) Ignition switch off 10 kΩ or higher
      F55-32 (BTH+) - A27-2 (IG2D) Ignition switch off 10 kΩ or higher
      F55-32 (BTH+) - F55-14 (SPDI) Ignition switch off 10 kΩ or higher
      F55-33 (BTH-) - F56-7 (AM21) Ignition switch off 10 kΩ or higher
      F55-33 (BTH-) - F55-1 (AM22) Ignition switch off 10 kΩ or higher
      F55-33 (BTH-) - A26-2 (+B2) Ignition switch off 10 kΩ or higher
      F55-33 (BTH-) - A27-5 (+B1) Ignition switch off 10 kΩ or higher
      F55-33 (BTH-) - A27-6 (MREL) Ignition switch off 10 kΩ or higher
      F55-33 (BTH-) - A27-1 (IG2) Ignition switch off 10 kΩ or higher
      F55-33 (BTH-) - F56-1 (ACCD) Ignition switch off 10 kΩ or higher
      F55-33 (BTH-) - F56-2 (IG1D) Ignition switch off 10 kΩ or higher
      F55-33 (BTH-) - A27-2 (IG2D) Ignition switch off 10 kΩ or higher
      F55-33 (BTH-) - F55-14 (SPDI) Ignition 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. Measure the resistance according to the value(s) in the table below. (w/o power switch)

      A01UZIWE02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      		 - -
      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F55-32 (BTH+) - F55-1 (BATT) Ignition switch off 10 kΩ or higher
      F55-32 (BTH+) - A26-2 (+B2) Ignition switch off 10 kΩ or higher
      F55-32 (BTH+) - A27-5 (+B1) Ignition switch off 10 kΩ or higher
      F55-32 (BTH+) - A27-6 (MREL) Ignition switch off 10 kΩ or higher
      F55-32 (BTH+) - A27-1 (IG2) Ignition switch off 10 kΩ or higher
      F55-32 (BTH+) - F55-14 (SPDI) Ignition switch off 10 kΩ or higher
      F55-33 (BTH-) - F55-1 (BATT) Ignition switch off 10 kΩ or higher
      F55-33 (BTH-) - A26-2 (+B2) Ignition switch off 10 kΩ or higher
      F55-33 (BTH-) - A27-5 (+B1) Ignition switch off 10 kΩ or higher
      F55-33 (BTH-) - A27-6 (MREL) Ignition switch off 10 kΩ or higher
      F55-33 (BTH-) - A27-1 (IG2) Ignition switch off 10 kΩ or higher
      F55-33 (BTH-) - F55-14 (SPDI) Ignition 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.

    11. Connect the battery smart unit connector.

    12. Install the No. 1 hybrid battery exhaust duct.

    13. Connect the power management control ECU connectors.

    14. Install the IG2 No. 2 fuse, IGCT No. 2 fuse, AM2 fuse. (w/ power switch)

    15. Install the IG2 No. 2 fuse, IGCT No. 2 fuse, ECU-B No. 2 fuse. (w/o power switch)


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. 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 ignition switch to ON (READY), unless instructed by the repair manual because this may cause a malfunction.

    2. Remove the No. 1 hybrid battery exhaust duct Click here.

    3. Disconnect the battery smart unit connector.

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

    5. Turn the ignition switch to ON (IG).

    6. A01V1YQE02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Battery Smart Unit)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      K32-1 (BTH+) - K32-6 (GND) Ignition switch ON (IG) 2.3 to 2.7 V
      K32-4 (BTH-) - K32-6 (GND) Ignition switch ON (IG) 2.3 to 2.7 V

      Note

      Turning the ignition switch to 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 ignition switch off.

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

    9. A01UZG9E02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Battery Smart Unit)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      K32-1 (BTH+) - K32-4 (BTH-) Ignition switch off 4.4 to 5.4 kΩ

      Tech Tips

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

    10. Connect the battery smart unit connector.

    11. Install the No. 1 hybrid battery exhaust duct.


    OK

    REPLACE BATTERY SMART UNIT Click here

    NG

    REPLACE POWER MANAGEMENT CONTROL ECU Click here