HYBRID CONTROL SYSTEM, Diagnostic DTC:P1C8549

DTC Code DTC Name
P1C8549 High Voltage Power Resource Internal Electronic Failure

DESCRIPTION

The hybrid vehicle control ECU monitors the system internal operation, it will store a DTC and perform fail-safe control if it detects the following malfunction.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Warning Indicate
P1C8549 High Voltage Power Resource Internal Electronic Failure

Battery overcurrent or overload current occurs due to a malfunction in the high-voltage circuit between the hybrid system, battery and inverter.

(1 trip detection logic)

  • Hybrid vehicle control ECU

  • HV battery junction block assembly

  • Battery voltage sensor

  • Wire harness or connector

 Does not come on

Master Warning Light:

Comes on
Related Data List
DTC No. Data List
P1C8549

  • Hybrid Battery Current

  • Hybrid Battery Voltage

  • VL-Voltage before Boosting

  • VH-Voltage after Boosting

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. Drive the vehicle for approximately 10 minutes according to the freeze frame data items "Vehicle Speed", "Accelerator Position" and "Hybrid Battery Current".

  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 or N/A, perform driving pattern again.

WIRING DIAGRAM

B004PBJE29
*a HV Battery Junction Block Assembly (Battery Current Sensor)
*b Battery Voltage Sensor

PROCEDURE


  1. 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.


      Powertrain > Hybrid Control > Trouble Codes
      Result
      Proceed to
      P1C8549 only is output.
      DTCs other than P1C8549 is also output.

    5. Turn the power switch off.


    DTCs other than P1C8549 is also output.

    GO TO DTC CHART (HYBRID CONTROL SYSTEM) Click here

    P1C8549 only is output.

  2. READ VALUE USING GTS (HYBRID BATTERY CURRENT)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / Data List / Hybrid Battery Current.


      Powertrain > Hybrid Control > Data List
      Tester Display
      Hybrid Battery Current

    4. Read the Data List.

      Result
      Result Proceed to
      The value of Hybrid Battery Current is between -4 A and 4 A A
      Other than above B

    5. Turn the power switch off.


    A

    REPLACE HYBRID VEHICLE CONTROL ECU Click here

    B

  3. CHECK HARNESS AND CONNECTOR (BATTERY VOLTAGE SENSOR - HV BATTERY JUNCTION BLOCK ASSEMBLY)

    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 No. 1 HV battery cover panel RH.

      Tech Tips

      Click here

    3. B004PP1N04

      Disconnect the z10 battery current sensor connector from the HV battery junction block assembly.

      Note

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

    4. Remove the No. 1 hybrid battery exhaust duct.

      Tech Tips

      Click here

    5. Disconnect the z9 battery voltage sensor connector.

      Note

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

    6. B004QX0C04
      *a

      Rear view of wire harness connector

      (to Battery Voltage Sensor)
      *b

      Front view of wire harness connector

      (to HV Battery Junction Block Assembly (Battery Current Sensor))

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      z9-5 (IB0) - z10-4 (IB0) Power switch off Below 1 Ω
      z9-12 (GIB) - z10-3 (GIB) Power switch off Below 1 Ω
      z9-6 (VIB) - z10-1 (VIB) Power switch off Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      z9-5 (IB0) or z10-4 (IB0) - Body ground and other terminals Power switch off 10 kΩ or higher
      z9-12 (GIB) or z10-3 (GIB) - Body ground and other terminals Power switch off 10 kΩ or higher
      z9-6 (VIB) or z10-1 (VIB) - Body ground and other terminals Power switch off 10 kΩ or higher

      Tech Tips

      As the battery harness is not available as a supply part, if the harness cannot be repaired, replace the HV battery.

    7. Reconnect the z9 battery voltage sensor connector.

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

    9. Reconnect the z10 battery current sensor connector to the HV battery junction block assembly.

    10. Install the No. 1 HV battery cover panel RH.

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HYBRID BATTERY THERMISTOR Click here

    OK

  4. CHECK HV BATTERY JUNCTION BLOCK ASSEMBLY (BATTERY CURRENT SENSOR (IB))

    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 No. 1 hybrid battery exhaust duct.

      Tech Tips

      Click here

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

    4. Turn the power switch on (IG).

    5. B004PINC32
      *a

      Component with harness connected

      (Battery Voltage Sensor)

      Using a toyota electrical tester set to 40 V, measure the VIB voltage according to the value(s) in the table below.

      Tester Connection Tester Connection
      z9-6 (VIB) - z9-12 (GIB) Power switch on (IG)

      Note


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

      • Be sure to set the toyota electrical tester to 40 V when performing this test.

    6. B004PINC33
      *a

      Component with harness connected

      (Battery Voltage Sensor)

      Using a toyota electrical tester set to 4 V, measure the IB0 voltage according to the value(s) in the table below.

      Tester Connection Tester Connection
      z9-5(IB0) - z9-12(GIB) Power switch on (IG)

      Note

      Be sure to set the toyota electrical tester to 4 V when performing this test.

    7. Compare the measured values of the IB0 terminal voltage and VIB terminal voltage using the following formula:

      IB0 voltage - VIB Voltage / 2 = less than 0.081 V
      IB0 voltage - VIB Voltage / 2 = -0.081 V or higher
      Result
      Result Proceed to
      Within the specified range above A
      Other than above B

    8. Turn the power switch off.

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

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

      Tech Tips

      When the power switch is on (IG) the actual current will be approximately 0 A. The following graph shows the relation of the actual output voltage of the battery current sensor terminal IB0 and actual current used for DTC judgment.

      B004OU6E03

    B

    REPLACE HV BATTERY JUNCTION BLOCK ASSEMBLY Click here

    A

  5. REPLACE BATTERY VOLTAGE SENSOR

    Tech Tips

    Click here

    Result
    Proceed to
    NEXT

    NEXT

  6. SIMULATION TEST


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Clear the DTCs.


      Powertrain > Hybrid Control > Clear DTCs

    4. Drive the vehicle on urban roads for approximately 10 minutes.

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

    6. Turn the power switch on (IG) and wait for 10 seconds or more.

      Result
      Proceed to
      NEXT

    NEXT

  7. RECONFIRM 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.


      Powertrain > Hybrid Control > Trouble Codes

    4. Read output DTCs.

    5. Turn the power switch off.

      Result
      Result Proceed to
      DTCs are not output A
      P1C8549 is output B

    A

    COMPLETED

    B

    REPLACE HV BATTERY JUNCTION BLOCK ASSEMBLY Click here