Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM1000000026PU8
Model Year Start: 2023 Model: Corolla HV Prod Date Range: [09/2022 -           ]
Title: HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with PA10): P1C8449; High Voltage Power Resource Circuit Short during Ready ON; 2023 - 2025 MY Corolla HV [09/2022 -        ]

DTC

P1C8449

High Voltage Power Resource Circuit Short during Ready ON

DTC SUMMARY

MALFUNCTION DESCRIPTION

The hybrid vehicle control ECU monitors the high-voltage wiring between the HV battery and inverter with converter assembly and detects an open circuit malfunction.

HINT:

  • This DTC is differentiated from P1C8349 based on detection timing (after ignition switch is turned to ON (READY)). If P1C8349 is also output at the same time, first perform troubleshooting for P1C8349.
  • If there is a SMRG stuck open malfunction, only P1C8449 is output.

The cause of this malfunction may be one of the following:

Inverter voltage sensor (VH) internal circuit malfunction

  • Voltage sensor (VH) malfunction
  • Motor generator control ECU (MG ECU) malfunction
  • Communication (wire harness) malfunction

High voltage system malfunction

  • HV battery malfunction
  • HV battery junction block assembly malfunction
  • Inverter with converter assembly malfunction
  • High-voltage wire harness malfunction
  • High-voltage connector or connection malfunction

Low-voltage circuit (12 V) malfunction

  • Hybrid vehicle control ECU malfunction
  • HV battery junction block assembly malfunction
  • Low voltage wire harness malfunction
  • Low voltage connector malfunction

DESCRIPTION

Refer to the description for DTC P0AD911.

Click here 2023 - 2025 MY Corolla HV [09/2022 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with PA10): P0AD911; Hybrid/EV Battery Positive Contactor Circuit Short to Ground+

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

Note

P1C8449

High Voltage Power Resource Circuit Short during Ready ON

High-voltage circuit malfunctions between the HV battery and inverter with converter assembly.

The voltage before boosting continues to be out of the HV battery voltage range or the integrated value of variation amount of the voltage before boosting for a specified period of time is large while the ignition switch is on (READY).

The EV electric battery fuse is blown, the service plug grip is removed, SMRB or SMRG remains open, or the high-voltage cable has an open circuit.

(1 trip detection logic)

  • HV battery junction block assembly
  • Wire harness or connector
  • Hybrid vehicle control ECU

Comes on

Master Warning:

Comes on

SAE Code:

P3004

MONITOR DESCRIPTION

A malfunction is detected and the MIL is illuminated when the following condition is met:

A large fluctuation of DC/DC converter voltage has occurred due to power cable disconnection.

MONITOR STRATEGY

Related DTCs

P3004 (INF P1C8449): Power Cable Malfunction

Required sensors/components

DC/DC converter, HV battery

Frequency of operation

-

Duration

TMC's intellectual property

MIL operation

1 driving cycle

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

The monitor will run whenever the following DTCs are not stored

TMC's intellectual property

Other conditions belong to TMC's intellectual property

-

TYPICAL MALFUNCTION THRESHOLDS

TMC's intellectual property

-

COMPONENT OPERATING RANGE

Hybrid vehicle control ECU

P3004 (INF P1C8449) is not detected

CONFIRMATION DRIVING PATTERN

HINT:

  • After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.

    Click here 2023 - 2025 MY Corolla HV [09/2022 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with PA10): UTILITY

  • When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.

    Click here 2023 - 2025 MY Corolla HV [09/2022 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with PA10): DTC CHECK / CLEAR

  1. Connect the GTS to the DLC3.
  2. Turn the ignition switch to ON and turn the GTS on.
  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  4. Turn the ignition switch off and wait for 2 minutes or more.
  5. Turn the ignition switch to ON and turn the GTS on.
  6. Turn the ignition switch to ON (READY) and wait for 3 minutes or more. [*1]

    HINT:

    • According to the display on the GTS, read the Data List and monitor the values of "Hybrid/EV Battery Voltage" and "VL-Voltage before Boosting" for 3 minutes. If the difference between "Hybrid/EV Battery Voltage" and "VL-Voltage before Boosting" is always less than 50 V, the vehicle has returned to normal.
    • [*1]: Normal judgment procedure.

      The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.

  7. Enter the following menus: Powertrain / Hybrid Control / Utility / All Readiness.
  8. Check the DTC judgment result.

    HINT:

    • 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 the normal judgment procedure again.

WIRING DIAGRAM

Refer to the wiring diagram for the HV Battery High-voltage Line Circuit.

Click here 2023 - 2025 MY Corolla HV [09/2022 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with PA10): HV Battery High-voltage Line Circuit+

CAUTION / NOTICE / HINT

CAUTION:

Refer to the precautions before inspecting high voltage circuit.

Click here 2023 - 2025 MY Corolla HV [09/2022 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with PA10): PRECAUTION

NOTICE:

  • After the ignition switch is turned off, there may be a waiting time before disconnecting the negative (-) auxiliary battery terminal.

    Click here 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 -        ]; SETUP: WHEN DISCONNECTING OR RECONNECTING BATTERY TERMINAL: BEFORE DISCONNECTING BATTERY

  • When disconnecting and reconnecting the auxiliary battery

    HINT:

    When disconnecting and reconnecting the auxiliary battery, there is an automatic learning function that completes learning when the respective system is used.

    Click here 2023 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 - 11/2022]; SETUP: WHEN DISCONNECTING OR RECONNECTING BATTERY TERMINAL: AUTOMATIC LEARNING CHART 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [11/2022 -        ]; SETUP: WHEN DISCONNECTING OR RECONNECTING BATTERY TERMINAL: AUTOMATIC LEARNING CHART

HINT:

  • P1C8449 may be output as a result of the malfunction indicated by the DTCs in table below.
    1. The chart above is listed in inspection order of priority.
    2. Check DTCs that are output at the same time by following the listed order. (The main cause of the malfunction can be determined without performing unnecessary inspections.)

      Malfunction Content

      System

      Relevant DTC

      Microcomputer malfunction

      Hybrid control system

      P0A1B49

      Drive Motor "A" Control Module Internal Electronic Failure

      P060647

      Hybrid/EV Powertrain Control Module Processor Watchdog / Safety MCU Failure

      Motor generator control system

      P0A1B1F

      Generator Control Module Circuit Intermittent

      P0A1A47

      Generator Control Module Watchdog / Safety μC Failure

      P0A1A49

      Generator Control Module Internal Electronic Failure

      P1C2A1C

      Generator A/D Converter Circuit Circuit Voltage Out of Range

      P1C2A49

      Generator A/D Converter Circuit Internal Electronic Failure

      P313383

      Communication Error from Generator to Drive Motor "A" Value of Signal Protection Calculation Incorrect

      P313386

      Communication Error from Generator to Drive Motor "A" Signal Invalid

      Hybrid battery system

      P060687

      Hybrid/EV Battery Energy Control Module Processor to Monitoring Processor Missing Message

      P060A47

      Hybrid/EV Battery Energy Control Module Monitoring Processor Watchdog / Safety MCU Failure

      P060A87

      Hybrid/EV Battery Energy Control Module Processor from Monitoring Processor Missing Message

      P060B16

      Hybrid/EV Battery Energy Control Module A/D Processing Circuit Voltage Below Threshold

      P060B49

      Hybrid/EV Battery Energy Control Module A/D Processing Internal Electronic Failure

      Power source circuit malfunction

      Motor generator control system

      P06D61C

      Generator Control Module Offset Power Circuit Voltage Out of Range

      Hybrid battery system

      P1CBB12

      Hybrid/EV Battery Current Sensor Power Supply Circuit Short to Auxiliary Battery

      P1CBB14

      Hybrid/EV Battery Current Sensor Power Supply Circuit Short to Ground or Open

      Communication system malfunction

      Hybrid control system

      P312387

      Lost Communication with Drive Motor Control Module "A" from Hybrid/EV Control Module Missing Message

      U011187

      Lost Communication with Hybrid/EV Battery Energy Control Module "A" Missing Message

      Motor generator control system

      P313387

      Communication Error from Generator to Drive Motor "A" Missing Message

      Sensor and actuator circuit malfunction

      Hybrid control system

      P0ABF00

      Hybrid/EV Battery Current Sensor "A" Circuit Range/Performance

      P0AD911

      Hybrid/EV Battery Positive Contactor Circuit Short to Ground

      P0AD915

      Hybrid/EV Battery Positive Contactor Circuit Short to Auxiliary Battery or Open

      P0ADD11

      Hybrid/EV Battery Negative Contactor Circuit Short to Ground

      P0ADD15

      Hybrid/EV Battery Negative Contactor Circuit Short to Auxiliary Battery or Open

      Motor generator control system

      P0D2D16

      Drive Motor "A" Inverter Voltage Sensor(VH) Circuit Voltage Below Threshold

      P0D2D17

      Drive Motor "A" Inverter Voltage Sensor(VH) Circuit Voltage Above Threshold

      Hybrid battery system

      P0ABF11

      Hybrid/EV Battery Current Sensor "A" Circuit Short to Ground

      P0ABF15

      Hybrid/EV Battery Current Sensor "A" Circuit Short to Auxiliary Battery or Open

      P0ABF28

      Hybrid/EV Battery Current Sensor "A" Signal Bias Level Out of Range / Zero Adjustment Failure

      P0ABF2A

      Hybrid/EV Battery Current Sensor "A" Signal Stuck In Range

      P0B0E11

      Hybrid/EV Battery Current Sensor "B" Circuit Short to Ground

      P0B0E15

      Hybrid/EV Battery Current Sensor "B" Circuit Short to Auxiliary Battery or Open

      P0B1362

      Hybrid/EV Battery Current Sensor "A"/"B" Signal Compare Failure

      System malfunction

      Hybrid control system

      P0A1F94

      Hybrid/EV Battery Energy Control Module Unexpected Operation

      P0D2D1C

      Drive Motor "A" Inverter Voltage Sensor Voltage Out of Range

      P0E311C

      Boosting Converter Voltage Sensor "A" Voltage Out of Range

      P1C2D62

      Hybrid/EV Battery "A" Voltage Sensor/Boosting Converter Voltage Sensor "A" Signal Compare Failure

      P1C8349

      High Voltage Power Resource Circuit Voltage Sensor after Boosting Malfunction

      P300449

      High Voltage Power Resource Circuit Short during Pre-Charge

      Motor generator control system

      P1CB69E

      Drive Motor "A" Inverter Voltage Sensor(VH) Stuck On

      P0CA300

      DC/DC Converter Step Up Voltage Performance

      Hybrid battery system

      P300016

      Hybrid/EV Battery Control System Circuit Voltage Below Threshold

PROCEDURE

1.

CLEAR DTC

Click here 2023 - 2025 MY Corolla HV [09/2022 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with PA10): P06881F; ECM/PCM Power Relay Sense Circuit Intermittent+

NEXT

2.

CHECK DTC OUTPUT (HYBRID CONTROL)

(a) With the vehicle stopped, apply the parking brake and turn the ignition switch to ON (READY).

NOTICE:

Perform this test with the AUTO function (shift-linked function) of the electric parking brake system off.

HINT:

  • If the ignition switch could not be turned to ON (READY), turn the ignition switch off and check for DTCs after turning the ignition switch to ON (READY) again.
  • Because P300449 uses 2 trip detection logic, the DTC detection conditions need to be met 2 times.
  • When the parking brake indicator (red) is illuminated after the electric parking brake switch assembly has been pulled to the lock side, the maximum amount of braking force is applied if the electric parking brake switch assembly is pulled to the lock side one more time.

(b) Ensure the safety of the areas in front and at the back of the vehicle.

(c) Move the shift lever to D and depress both the accelerator pedal and brake pedal at the same time.

HINT:

Depressing both the accelerator pedal and brake pedal at the same time causes the HV battery current to flow and ensures that there is no problem with the high-voltage wiring.

(d) Check for DTCs.

Powertrain > Hybrid Control > Trouble Codes

Result

Proceed to

P1C8449 is output, or no DTCs are output.

A

Ignition switch could not be turned to ON (READY) and DTC P1C8349 is output.

B

P0A9563 is also output.

C

(e) Turn the ignition switch off.

B

GO TO DTC CHART (P1C8349)

C

GO TO DTC CHART (P0A9563)

A

3.

CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR)

Click here 2023 - 2025 MY Corolla HV [09/2022 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with PA10): P056014; System Voltage (BATT) Circuit Short to Ground or Open+

NG

CONNECT SECURELY

OK

4.

CHECK CONNECTOR CONNECTION CONDITION (FLOOR WIRE CONNECTOR)

Click here 2023 - 2025 MY Corolla HV [09/2022 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with PA10): P0AA000; Hybrid/EV Battery Positive Contactor Circuit Stuck Closed+

Result

Proceed to

OK

A

NG (The connector is not connected securely.)

B

NG (The terminals are not making secure contact or are deformed, or water or foreign matter exists in the connector.)

C

B

CONNECT SECURELY

C

REPAIR OR REPLACE HARNESS OR CONNECTOR

A

5.

CHECK CONNECTOR CONNECTION CONDITION (HV BATTERY JUNCTION BLOCK ASSEMBLY CONNECTOR)

Click here 2023 - 2025 MY Corolla HV [09/2022 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with PA10): P0AA000; Hybrid/EV Battery Positive Contactor Circuit Stuck Closed+

NG

CONNECT SECURELY

OK

6.

CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - HV BATTERY JUNCTION BLOCK ASSEMBLY)

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

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.

(b) Disconnect the HV battery junction block assembly connector.

(c) Disconnect the hybrid vehicle control ECU connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I3-3 (SMRB) - O193-4 (SMRB)

Ignition switch off

Below 1 Ω

I3-27 (SMRG) - O193-6 (SMRG)

Ignition switch off

Below 1 Ω

(e) Reconnect the hybrid vehicle control ECU connector.

(f) Reconnect the HV battery junction block assembly connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

7.

CHECK HARNESS AND CONNECTOR (HV BATTERY JUNCTION BLOCK ASSEMBLY - BODY GROUND)

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

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.

(b) Disconnect the HV battery junction block assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

O193-2 (GND) - Body ground

Ignition switch off

Below 1 Ω

(d) Reconnect the HV battery junction block assembly connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

8.

REPLACE HV BATTERY JUNCTION BLOCK ASSEMBLY

Click here 2023 - 2025 MY Corolla Corolla HV [09/2022 -        ]; HYBRID / BATTERY CONTROL: HV RELAY ASSEMBLY (for LITHIUM-ION BATTERY): REMOVAL

NEXT

9.

CLEAR DTC

CAUTION:

Be sure to wear insulated gloves.

(a) Install the service plug grip.

(b) Clear the DTCs.

Powertrain > Hybrid Control > Clear DTCs

(c) Turn the ignition switch off and wait for 2 minutes or more.

NEXT

10.

CHECK HYBRID VEHICLE CONTROL ECU (CHECK FOR NORMAL OPERATION)

(a) Turn the ignition switch to ON (READY).

(b) According to the display on the GTS, read the Data List and monitor the values of "Hybrid/EV Battery Voltage" and "VL-Voltage before Boosting" for 3 minutes.

Powertrain > Hybrid Control > Data List

Tester Display

VL-Voltage before Boosting

Hybrid/EV Battery Voltage

Result

Proceed to

Difference between "Hybrid/EV Battery Voltage" and "VL-Voltage before Boosting" is always less than 50 V.

A

Difference between "Hybrid/EV Battery Voltage" and "VL-Voltage before Boosting" is 50 V or more.

B

(c) Turn the ignition switch off.

A

END

B

REPLACE HYBRID VEHICLE CONTROL ECU