Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001N32A
Model Year Start: 2021 Model: Corolla Prod Date Range: [04/2020 - 09/2022]
Title: HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with P610): P0A1F94; Hybrid/EV Battery Energy Control Module Unexpected Operation; 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]

DTC

P0A1F94

Hybrid/EV Battery Energy Control Module Unexpected Operation

DTC SUMMARY

MALFUNCTION DESCRIPTION

The hybrid vehicle control ECU (main CPU) monitors the battery ECU assembly.

The cause of this malfunction may be the following:

Battery ECU assembly internal malfunction

  • Battery ECU assembly malfunction

DESCRIPTION

The hybrid vehicle control ECU (main CPU) monitors the battery ECU assembly and stores this DTC when it detects a malfunction.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P0A1F94

Hybrid/EV Battery Energy Control Module Unexpected Operation

The battery ECU assembly value received by the hybrid vehicle control ECU (main CPU) exceeds the threshold for a certain period of time.

(1 trip detection logic)
  • No. 1 HV supply stack sub-assembly
  • No. 2 HV supply stack sub-assembly
  • Battery ECU assembly

Comes on

Master Warning:

Comes on

MONITOR DESCRIPTION

The battery ECU assembly monitors the hybrid vehicle control ECU via CAN communication. If the battery ECU assembly detects a malfunction in the hybrid vehicle control ECU, it will illuminate the MIL and store a DTC.

MONITOR STRATEGY

Related DTCs

P0A1F (INF P0A1F94): Battery Energy Control Module

Required sensors/components

Battery ECU assembly

Frequency of operation

Continuous

Duration

TMC's intellectual property

MIL operation

1 driving cycle

Sequence of operation

None

MONITOR STRATEGY

The monitor will run whenever the following DTCs are not stored

TMC's intellectual property

Other conditions belong to TMC's intellectual property

-

TYPICAL ENABLING CONDITIONS

TMC's intellectual property

-

COMPONENT OPERATING RANGE

Hybrid vehicle control ECU

P0A1F (INF P0A1F94) 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 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with P610): UTILITY

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

    Click here 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with P610): DTC CHECK / CLEAR

  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 and wait for 2 minutes or more.
  5. Turn the power switch on (IG) and turn the Techstream on.
  6. Turn the power switch on (READY) and wait for 10 seconds or more. [*1]

    HINT:

    [*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 or N/A, perform the normal judgment procedure again.

PROCEDURE

1.

CHECK DTC OUTPUT (HYBRID CONTROL AND HV BATTERY)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Read and record the DTCs and freeze frame data.

Powertrain > Hybrid Control > Trouble Codes

Powertrain > HV Battery > Trouble Codes

Result

Proceed to

P0A1F94 only is output, or DTCs except the ones in the table below are also output.

A

DTCs of hybrid control system except P0A1F94 are output.

B

Any of the following DTCs including pending DTCs are also output.

C

System

Relevant DTC

Hybrid battery system

P1A001C

Hybrid Battery Stack 2 Cell Voltage Detection Voltage Out of Range

P301A1C

Hybrid Battery Stack 1 Cell Voltage Detection Voltage Out of Range

(d) Turn the ignition switch off.

A

REPLACE BATTERY ECU ASSEMBLY

B

GO TO DTC CHART (HYBRID CONTROL SYSTEM)

C

2.

CHECK DTC

(a) Check the DTCs that were output when the vehicle was brought to the workshop.

Result

Proceed to

"P1A001C" is also output.

A

"P301A1C" is also output.

B
B

GO TO STEP 7

A

3.

CHECK CONNECTOR CONNECTION CONDITION (BATTERY ECU ASSEMBLY CONNECTOR)

CAUTION:

Be sure to wear insulated gloves and protective goggles.

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

NOTICE:

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.

(b) Remove the No. 1 HV battery protector.

Click here 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; HYBRID / BATTERY CONTROL: BATTERY ECU (for LITHIUM-ION BATTERY): REMOVAL+

(c) Check the connector connections and contact pressure of the relevant terminals for the battery ECU assembly.

Click here 2019 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 -        ]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: ELECTRONIC CIRCUIT INSPECTION PROCEDURE

OK:

The connectors are connected securely and there are no contact problems.

(d) Install the No. 1 HV battery protector.

Result

Proceed to

OK

A

Not connected securely

The terminals are not damaged or corroded

B

Not connected securely

The terminals are damaged or corroded

C
B

CONNECT SECURELY
C

REPLACE NO. 2 HV SUPPLY STACK SUB-ASSEMBLY

A

4.

CHECK FREEZE FRAME DATA (HV BATTERY)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Enter the following menus: Powertrain / HV battery / Trouble Codes.

(d) Read the value of freeze frame data items "Hybrid/EV Battery Cell 29 Voltage" through "Hybrid/EV Battery Cell 56 Voltage" for DTC P1A001C and make a note if the value of any is 1.6 V or less.

Powertrain > HV Battery > Trouble Codes

(e) Turn the power switch off.

Result

Proceed to

The voltage of any hybrid battery cell from 29 to 37 is 1.6 V or less.

A

The voltage of any hybrid battery cell from 38 to 56 is 1.6 V or less.

B
B

GO TO STEP 6

A

5.

CHECK NO. 2 HV SUPPLY STACK SUB-ASSEMBLY (HYBRID BATTERY CELL 29 TO 37 VOLTAGE)

Click here 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY with P610): P0E2D00; Hybrid/EV Battery Energy Control Module Hybrid/EV Battery Monitor Performance+

Result

Proceed to

The voltage between the terminals is 1.6 V or less.

A

Other than above

B
A

REPLACE NO. 2 HV SUPPLY STACK SUB-ASSEMBLY

B

REPLACE BATTERY ECU ASSEMBLY

6.

CHECK NO. 2 HV SUPPLY STACK SUB-ASSEMBLY (HYBRID BATTERY CELL 38 TO 56 VOLTAGE)

Click here 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY with P610): P0E2D00; Hybrid/EV Battery Energy Control Module Hybrid/EV Battery Monitor Performance+

Result

Proceed to

The voltage between the terminals is 1.6 V or less.

A

Other than above

B
A

REPLACE NO. 2 HV SUPPLY STACK SUB-ASSEMBLY

B

REPLACE BATTERY ECU ASSEMBLY

7.

CHECK CONNECTOR CONNECTION CONDITION (BATTERY ECU ASSEMBLY CONNECTOR)

CAUTION:

Be sure to wear insulated gloves and protective goggles.

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

NOTICE:

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.

(b) Remove the No. 1 HV battery protector.

Click here 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; HYBRID / BATTERY CONTROL: BATTERY ECU (for LITHIUM-ION BATTERY): REMOVAL+

(c) Check the connector connections and contact pressure of the relevant terminals for the battery ECU assembly.

Click here 2019 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 -        ]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: ELECTRONIC CIRCUIT INSPECTION PROCEDURE

OK:

The connectors are connected securely and there are no contact problems.

Result:

Result

Proceed to

OK

A

Not connected securely

The terminals are not damaged or corroded

B

Not connected securely

The terminals are damaged or corroded

C

(d) Install the No. 1 HV battery protector.

B

CONNECT SECURELY
C

REPLACE NO. 1 HV SUPPLY STACK SUB-ASSEMBLY

A

8.

CHECK FREEZE FRAME DATA (HV BATTERY)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Enter the following menus: Powertrain / HV battery / Trouble Codes.

(d) Read the value of freeze frame data items "Hybrid/EV Battery cell 1 voltage" through "Hybrid/EV Battery cell 28 voltage" for DTC P301A1C and make a note if the value of any is 1.6 V or less.

Powertrain > HV Battery > Trouble Codes

(e) Turn the power switch off.

Result

Proceed to

The voltage of any hybrid battery cell from 1 to 19 is 1.6 V or less.

A

The voltage of any hybrid battery cell from 20 to 28 is 1.6 V or less.

B
B

GO TO STEP 10

A

9.

CHECK NO. 1 HV SUPPLY STACK SUB-ASSEMBLY (HYBRID BATTERY CELL 1 TO 19 VOLTAGE)

Click here 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY with P610): P0E2D00; Hybrid/EV Battery Energy Control Module Hybrid/EV Battery Monitor Performance+

Result

Proceed to

The voltage between the terminals is 1.6 V or less.

A

Other than above

B
A

REPLACE NO. 1 HV SUPPLY STACK SUB-ASSEMBLY

B

REPLACE BATTERY ECU ASSEMBLY

10.

CHECK NO. 1 HV SUPPLY STACK SUB-ASSEMBLY (HYBRID BATTERY CELL 20 TO 28 VOLTAGE)

Click here 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY with P610): P0E2D00; Hybrid/EV Battery Energy Control Module Hybrid/EV Battery Monitor Performance+

Result

Proceed to

The voltage between the terminals is 1.6 V or less.

A

Other than above

B
A

REPLACE NO. 1 HV SUPPLY STACK SUB-ASSEMBLY

B

REPLACE BATTERY ECU ASSEMBLY