HYBRID CONTROL SYSTEM, Diagnostic DTC:P0AA749

DTC Code DTC Name
P0AA749 Hybrid/EV Battery Voltage Isolation Sensor Circuit Internal Electronic Failure

DESCRIPTION

The hybrid vehicle control ECU assembly monitors the insulation monitoring circuit located in the battery ECU assembly and detects malfunctions.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Warning Indicate
P0AA749 Hybrid/EV Battery Voltage Isolation Sensor Circuit Internal Electronic Failure

Malfunction in the insulation monitoring circuit in the battery ECU assembly

(1 trip detection logic)

  • Battery voltage sensor (for upper side)

  • Battery ECU assembly

  • Wire harness or connector

 Does not come on

Master Warning Light:

Comes on
Related Data List
DTC No. Data List
P0AA749 Short Wave Highest Value Level

CONFIRMATION DRIVING PATTERN

Tech Tips

After repairs have been completed, clear the DTCs and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.

Click here


  1. Connect the GTS to the DLC3.

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

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

  4. Turn the power switch off and wait for 2 minutes or more.

  5. Turn the power switch on (IG) and turn the GTS on.

  6. With power switch on (IG) and wait for 70 seconds or more.

  7. Enter the following menus: Powertrain / Hybrid Control / Utility / All Readiness.

  8. Check the DTC judgment result.

    Tech Tips


    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

    • If the judgment result shows INCOMPLETE, perform driving pattern again.

CAUTION / NOTICE / HINT

CAUTION:


  • B004STG

    Before the following operations are conducted, take precautions to prevent electric shock by turning the power switch off, wearing insulated gloves, and removing the service plug grip from HV battery.


    • Inspecting the high-voltage system

    • Disconnecting the low voltage connector of the inverter with converter assembly

    • Disconnecting the low voltage connector of the HV battery

  • B004Y5N

    To prevent electric shock, make sure to remove the service plug grip to cut off the high voltage circuit before servicing the vehicle.

  • B004SX1

    After removing the service plug grip from the HV battery, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.

  • B004W3JC19
    *a Without waiting for 10 minutes

    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.

  • Make sure to insulate the high-voltage connectors and terminals of the HV battery with insulating tape after removing it.

    If the HV battery stored without insulating the connectors and terminals, electric shock or fire may result.

  • B004X4P

    After removing the HV battery or the HV supply stack sub-assembly, keep it away from water. Exposure to water may cause the HV battery or the HV supply stack sub-assembly to produce heat, resulting in a fire.

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. CLEAR DTC

    Result
    Proceed to
    NEXT

    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. Read and record the DTCs and freeze frame data.


      Powertrain > Hybrid Control > Trouble Codes

    5. Clear the DTCs and freeze frame data.


      Powertrain > Hybrid Control > Clear DTCs

    6. Turn the power switch off.

      Result
      Proceed to
      NEXT

    NEXT

  2. SIMULATION TEST


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG) and wait for 70 seconds or more.

      Note

      Do not turn the power switch off until step 3 is complete.

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

    4. Check if DTCs are output.


      Powertrain > Hybrid Control > Trouble Codes
      Result
      Proceed to
      P0AA749 is not output.
      P0AA749 is output.

    P0AA749 is output.

    REPLACE BATTERY ECU ASSEMBLY Click here

    P0AA749 is not output.

  3. SIMULATION TEST

    Note

    Do not turn the power switch off while performing this inspection.


    1. With the vehicle and engine stopped, turn the power switch on (READY) with park (P) selected and wait for 70 seconds or more. (If the engine starts, wait until the engine stops.)

    2. While depressing the brake pedal without depressing the accelerator pedal, move the shift lever to select shift state drive (D) and wait for 1 minute. (Step A)

    3. Drive the vehicle 0.5 m (1.6 ft.) forward and perform step A.

    4. Drive the vehicle another 0.5 m (1.6 ft.) forward and perform step A. Repeat this procedure 5 times (minimum total driving distance: 2 m (6.6 ft.)).

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

    6. Check if DTCs are output.


      Powertrain > Hybrid Control > Trouble Codes
      Result
      Proceed to
      P0AA649 is not output.
      P0AA649 is output.

    7. Turn the power switch off.


    P0AA649 is output.

    GO TO DTC CHART (P0AA649) Click here

    P0AA649 is not output.

  4. CHECK HARNESS AND CONNECTOR (BATTERY ECU ASSEMBLY - BATTERY VOLTAGE SENSOR (for Upper Side))

    Result
    Proceed to
    OK
    NG

    CAUTION:

    Be sure to wear insulated gloves and protective goggles.


    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 No. 1 HV battery protector (for upper side).

      Click here

    3. Disconnect the d1 battery voltage sensor (for upper side) connector.

      CAUTION:

      Before disconnecting the d1 battery voltage sensor (for Upper Side) connector, disconnect the z14 and z15 connectors.

      B004V6WN02
    4. B004SHTN01

      Disconnect the d2 battery ECU assembly connector.

      Note


      • Insulate each disconnected high-voltage connector with insulating tape. Wrap the connector from the wire harness side to the end of the connector.

      • Before disconnecting the connector, check that it is not loose or disconnected.

    5. B004XGPC08
      *a

      Rear view of wire harness and connector

      (to Battery ECU Assembly)
      *b

      Rear view of wire harness and connector

      (to Battery Voltage Sensor (for Upper Side))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      d2-17 (GA0) - d1-19 (GA0) Power switch off Below 1 Ω
      d2-17 (GA0) or d1-19 (GA0) - Body ground and other terminals Power switch off 10 kΩ or higher

    6. Reconnect the d2 battery ECU assembly connector.

    7. B004V6WN02

      Reconnect the d1 battery voltage sensor (for upper side) connector.

      CAUTION:

      Before connecting the z14 and z15 battery voltage sensor (for Upper Side) connectors, connect the d1 connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT BATTERY VOLTAGE SENSOR (for Upper Side)

    Result
    Proceed to
    OK
    NG

    CAUTION:

    Be sure to wear insulated gloves and protective goggles.

    Note

    When checking the battery voltage sensor (for Upper Side) resistance, select a probe of appropriate thickness (approximately 0.5 mm) from the tester lead set, and perform the measurement.


    1. Disconnect the d1 battery voltage sensor (for upper side) connector.

      Click here

      CAUTION:

      Before disconnecting the d1 battery voltage sensor (for Upper Side) connector, disconnect the z14 and z15 connectors.

      B004V6WN02
    2. B004UHGC04
      *a

      Component without harness connected

      (Battery Voltage Sensor (for Upper Side))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      d1-19 (GA0) - z14-10 (GA0) Power switch off 5.88 to 6.12 kΩ
      d1-19 (GA0) or z14-10 (GA0) - Body ground and other terminals Power switch off 10 kΩ or higher

    3. Reconnect the d1 battery voltage sensor (for upper side) connector.

      CAUTION:

      Before connecting the z14 and z15 battery voltage sensor (for Upper Side) connectors, connect the d1 connector.

      B004V6WN02
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE BATTERY ECU ASSEMBLY Click here

    NG

    REPLACE BATTERY VOLTAGE SENSOR (for Upper Side) Click here