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 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

MONITOR DESCRIPTION

If the power management control ECU detects problem with serial communication with the battery smart unit, it will illuminate the MIL and set a DTC.

MONITOR STRATEGY

Related DTCs U029A (INF 123): Battery smart unit communication malfunction
Required sensors / components Battery smart unit
Frequency of operation Continuous
Duration TMC's intellectual property
MIL operation TMC's intellectual property
Sequence of operation None

TYPICAL ENABLING CONDITIONS

The monitor will run whenever the following DTCs are not present TMC's intellectual property
Other conditions belong to TMC's intellectual property -

TYPICAL MALFUNCTION THRESHOLDS

TMC's intellectual property -

COMPONENT OPERATING RANGE

Battery smart unit DTC U029A (INF 123) is not detected

CONFIRMATION DRIVING PATTERN

  1. Connect the Techstream to the DLC3.

  2. Turn the power switch on (IG) and turn the Techstream on.

  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

  4. Turn the power switch off.

  5. Turn the power switch on (READY) and turn the Techstream on.

  6. Perform a universal trip.

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

  8. Check that permanent DTCs are cleared.

    Tech Tips

    • If a permanent DTC is output, the system is malfunctioning.

    • If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

A011Z5OE01

INSPECTION PROCEDURE

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.

    Tech Tips

    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.

PROCEDURE

  1. CHECK DTC OUTPUT (HYBRID CONTROL)

    1. Connect the Techstream 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 other than U029A-123 are also output. B

    5. Turn the power switch off.

    6. Disconnect the Techstream from the DLC3.

    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 power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

    2. Disconnect connector I3 from the power management control ECU Click here.

    3. Remove the rear side seat back assembly LH Click here.

    4. Disconnect connector N18 from the battery smart unit.

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

      A011XW7E01
      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      I3-32 (BTH+) - N18-1 (BTH+) Power switch off Below 1 Ω
      I3-33 (BTH-) - N18-4 (BTH-) Power switch off Below 1 Ω
      N18-1 (BTH+) - N18-6 (GND) and Body ground Power switch off 10 kΩ or higher
      N18-4 (BTH-) - N18-6 (GND) and Body ground Power 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. Remove the PM IGCT fuse from the No. 2 engine room relay block.

      A011XBSE01
      Text in Illustration
      *1 No. 2 Engine Room Relay Block
      *2 PM IGCT fuse

    7. Remove the AM2 fuse from the engine room relay block and junction block assembly.

      A011YJEE01
      Text in Illustration
      *1 Engine Room Relay Block and Junction Block Assembly
      *2 AM2 fuse

    8. Remove the ECU-IG2 No. 1 fuse from the instrument panel junction block assembly.

      A011X0DE01
      Text in Illustration
      *1 Instrument Panel Junction Block Assembly
      *2 ECU-IG2 NO. 1 fuse

    9. Disconnect all connectors from the power management control ECU.

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

      A011YXCE18
      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      I3-32 (BTH+) - I4-7 (AM21) Power switch off 10 kΩ or higher
      I3-32 (BTH+) - I3-1 (AM22) Power switch off 10 kΩ or higher
      I3-32 (BTH+) - A38-2 (+B2) Power switch off 10 kΩ or higher
      I3-32 (BTH+) - A39-5 (+B1) Power switch off 10 kΩ or higher
      I3-32 (BTH+) - A39-6 (MREL) Power switch off 10 kΩ or higher
      I3-32 (BTH+) - A39-1 (IG2) Power switch off 10 kΩ or higher
      I3-32 (BTH+) - I4-1 (ACCD) Power switch off 10 kΩ or higher
      I3-32 (BTH+) I4-2 (IG1D) Power switch off 10 kΩ or higher
      I3-32 (BTH+) - A39-2 (IG2D) Power switch off 10 kΩ or higher
      I3-32 (BTH+) - I3-14 (SPDI) Power switch off 10 kΩ or higher
      I3-32 (BTH+) - A38-16 (GI) Power switch off 10 kΩ or higher
      I3-33 (BTH-) - I4-7 (AM21) Power switch off 10 kΩ or higher
      I3-33 (BTH-) - I3-1 (AM22) Power switch off 10 kΩ or higher
      I3-33 (BTH-) - A38-2 (+B2) Power switch off 10 kΩ or higher
      I3-33 (BTH-) - A39-5 (+B1) Power switch off 10 kΩ or higher
      I3-33 (BTH-) - A39-6 (MREL) Power switch off 10 kΩ or higher
      I3-33 (BTH-) - A39-1 (IG2) Power switch off 10 kΩ or higher
      I3-33 (BTH-) - I4-1 (ACCD) Power switch off 10 kΩ or higher
      I3-33 (BTH-) - I4-2 (IG1D) Power switch off 10 kΩ or higher
      I3-33 (BTH-) - A39-2 (IG2D) Power switch off 10 kΩ or higher
      I3-33 (BTH-) - I3-14 (SPDI) Power switch off 10 kΩ or higher
      I3-33 (BTH-) - A38-16 (GI) Power switch off 10 kΩ or higher
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      		 - -

      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 rear side seat back assembly LH.

    13. Connect the power management control ECU connectors.

    NG

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

    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 power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

    2. Remove the rear side seat back assembly LH Click here.

    3. Disconnect connector N18 from the battery smart unit.

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

    5. Turn the power switch on (IG).

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

      A011YIVE01
      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      N18-1 (BTH+) - N18-6 (GND) Power switch on (IG) 2.3 to 2.7 V
      N18-4 (BTH-) - N18-6 (GND) Power switch on (IG) 2.3 to 2.7 V
      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. Measure the resistance according to the value(s) in the table below.

      A011YIVE02
      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      N18-1 (BTH+) - N18-4 (BTH-) Power switch off 4.4 to 5.4 kΩ
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Battery Smart Unit)

      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 rear side seat back assembly LH.

    NG

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    OK

    REPLACE BATTERY SMART UNIT Click here