Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001RK0Y
Model Year Start: 2021 Model: Avalon HV Prod Date Range: [08/2020 -           ]
Title: HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): P1A001C,P301A1C; Hybrid Battery Stack 2 Cell Voltage Detection Voltage Out of Range; 2021 - 2022 MY Avalon HV [08/2020 -        ]

DTC

P1A001C

Hybrid Battery Stack 2 Cell Voltage Detection Voltage Out of Range

DTC

P301A1C

Hybrid Battery Stack 1 Cell Voltage Detection Voltage Out of Range

DESCRIPTION

The HV battery is composed of 70 cells (3.7 V each) in series. The battery ECU assembly monitors the voltage of each HV battery cell to detect malfunctions of the HV battery.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P1A001C

Hybrid Battery Stack 2 Cell Voltage Detection Voltage Out of Range

An open is detected in the HV battery cell voltage detection circuits of the No. 2 HV supply stack sub-assembly.

(1 trip detection logic)

  • No. 2 HV supply stack sub-assembly
  • Battery ECU assembly

Comes on

Master Warning Light:

Comes on

P301A1C

Hybrid Battery Stack 1 Cell Voltage Detection Voltage Out of Range

An open is detected in the HV battery cell voltage detection circuits of the No. 1 HV supply stack sub-assembly.

(1 trip detection logic)

  • No. 1 HV supply stack sub-assembly
  • Battery ECU assembly

Comes on

Master Warning Light:

Comes on

Related Data List

DTC No.

Data List

P1A001C

Hybrid/EV Battery Cell 1 to 70 Voltage

P301A1C

MONITOR DESCRIPTION

If the voltage of an HV battery cell is abnormal, the battery ECU assembly will determine that a malfunction has occurred. When the malfunction detection condition is satisfied, the battery ECU assembly will illuminate the MIL and store a DTC.

MONITOR STRATEGY

Related DTCs

P1A00 (INF P1A001C), P301A (INF P301A1C): Battery voltage detection circuits malfunction

Required sensors/components

Battery ECU assembly

Frequency of operation

Continuous

Duration

TMC's intellectual property

MIL operation

Immediately

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

Battery ECU assembly

DTC P1A00 (INF P1A001C) is not detected

DTC P301A (INF P301A1C) 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 Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): UTILITY

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

    Click here 2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): 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. With power switch on (IG) 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 / HV Battery / 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.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION:

  • 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
  • To prevent electric shock, make sure to remove the service plug grip to cut off the high voltage circuit before servicing the vehicle.
  • 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.
  • 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 2021 MY Avalon HV [08/2020 - 08/2021]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): PRECAUTION 2022 MY Avalon HV [08/2021 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): PRECAUTION

    HINT:

    Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

    *a

    Without waiting for 10 minutes

  • 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.

  • When disposing of an HV battery, make sure to return it through an authorized collection agent who is capable of handling it safely. If the HV battery is returned via the manufacturer specified route, it will be returned properly and in a safe manner by an authorized collection agent.

    *a

    Dealer

    *b

    Battery Collection Agent

    • Accidents such as electric shock may result if the HV battery is disposed of improperly or abandoned. Therefore, make sure to return all HV batteries through an authorized collection agent.
  • Before returning the HV battery, make sure to perform a recovery inspection.

    Click here 2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HV BATTERY (for LITHIUM-ION BATTERY): RECOVERY INSPECTION

  • Before returning the HV supply stack sub-assembly, make sure to perform a recovery inspection.

    Click here 2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HV BATTERY STACK (for LITHIUM-ION BATTERY): RECOVERY INSPECTION

  • Make a note of the output DTCs as some of them may be necessary for recovery inspection of the HV battery and HV supply stack sub-assemblies.
  • After removing the HV battery, keep it away from water. Exposure to water may cause the HV battery to produce heat, resulting in a fire.

NOTICE:

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 2021 MY Avalon Avalon HV [08/2020 - 08/2021]; INTRODUCTION: REPAIR INSTRUCTION: INITIALIZATION 2022 MY Avalon Avalon HV [08/2021 -        ]; INTRODUCTION: REPAIR INSTRUCTION: INITIALIZATION

PROCEDURE

1.

CHECK DTC OUTPUT (HV BATTERY, HYBRID CONTROL)

(a) Connect the Techstream to the DLC3.

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

(c) Enter the following menus: Powertrain / HV Battery and Hybrid Control / Trouble Codes.

(d) Check for DTCs.

Powertrain > HV Battery > Trouble Codes

Powertrain > Hybrid Control > Trouble Codes

Result

Proceed to

"P1A001C or P301A1C" only is output, or DTCs except the ones in the table below are also output.

A

DTCs of hybrid battery system in the table below are output.

B

DTCs of hybrid control system in the table below are output.

C

System

Relevant DTC

Hybrid battery system

P060A47

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

P060B49

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

P060687

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

P1AC413

Hybrid/EV Battery Stack 1 Current Interrupt Device Circuit Open

P1AC49E

Hybrid/EV Battery Stack 1 Current Interrupt Device Stuck On

P1AC513

Hybrid/EV Battery Stack 2 Current Interrupt Device Circuit Open

P1AC59E

Hybrid/EV Battery Stack 2 Current Interrupt Device Stuck On

Hybrid control system

P0A1F94

Hybrid/EV Battery Energy Control Module Unexpected Operation

(e) Turn the power switch off.

B

GO TO DTC CHART (HYBRID BATTERY SYSTEM)

C

GO TO DTC CHART (HYBRID CONTROL SYSTEM) 2021 MY Avalon HV [08/2020 - 08/2021]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY): DIAGNOSTIC TROUBLE CODE CHART 2022 MY Avalon HV [08/2021 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY): DIAGNOSTIC TROUBLE CODE CHART

A

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 6

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 hose.

Click here 2021 MY Avalon HV [08/2020 - 08/2021]; HYBRID / BATTERY CONTROL: BATTERY ECU (for LITHIUM-ION BATTERY): REMOVAL+ 2022 MY Avalon HV [08/2021 -        ]; 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 - 2022 MY Avalon Avalon HV [04/2018 -        ]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: ELECTRONIC CIRCUIT INSPECTION PROCEDURE

OK:

The connector is 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 hose.

B

CONNECT SECURELY

C

REPLACE NO. 2 HV SUPPLY STACK SUB-ASSEMBLY 2021 MY Avalon HV [08/2020 - 08/2021]; HYBRID / BATTERY CONTROL: HV BATTERY STACK (for LITHIUM-ION BATTERY): REMOVAL 2022 MY Avalon HV [08/2021 -        ]; HYBRID / BATTERY CONTROL: HV BATTERY STACK (for LITHIUM-ION BATTERY): REMOVAL

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 36 Voltage" through "Hybrid/EV Battery Cell 70 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.

NEXT

5.

CHECK NO. 2 HV SUPPLY STACK SUB-ASSEMBLY (HV BATTERY CELL VOLTAGE)

Click here 2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): 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 2021 MY Avalon HV [08/2020 - 08/2021]; HYBRID / BATTERY CONTROL: HV BATTERY STACK (for LITHIUM-ION BATTERY): REMOVAL 2022 MY Avalon HV [08/2021 -        ]; HYBRID / BATTERY CONTROL: HV BATTERY STACK (for LITHIUM-ION BATTERY): REMOVAL

B

REPLACE BATTERY ECU ASSEMBLY 2021 MY Avalon HV [08/2020 - 08/2021]; HYBRID / BATTERY CONTROL: BATTERY ECU (for LITHIUM-ION BATTERY): REMOVAL 2022 MY Avalon HV [08/2021 -        ]; HYBRID / BATTERY CONTROL: BATTERY ECU (for LITHIUM-ION BATTERY): REMOVAL

6.

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 hose.

Click here 2021 MY Avalon HV [08/2020 - 08/2021]; HYBRID / BATTERY CONTROL: BATTERY ECU (for LITHIUM-ION BATTERY): REMOVAL+ 2022 MY Avalon HV [08/2021 -        ]; 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 - 2022 MY Avalon Avalon HV [04/2018 -        ]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: ELECTRONIC CIRCUIT INSPECTION PROCEDURE

OK:

The connector is 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 hose.

B

CONNECT SECURELY

C

REPLACE NO. 1 HV SUPPLY STACK SUB-ASSEMBLY 2021 MY Avalon HV [08/2020 - 08/2021]; HYBRID / BATTERY CONTROL: HV BATTERY STACK (for LITHIUM-ION BATTERY): REMOVAL 2022 MY Avalon HV [08/2021 -        ]; HYBRID / BATTERY CONTROL: HV BATTERY STACK (for LITHIUM-ION BATTERY): REMOVAL

A

7.

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 35 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.

NEXT

8.

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

Click here 2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): 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 2021 MY Avalon HV [08/2020 - 08/2021]; HYBRID / BATTERY CONTROL: HV BATTERY STACK (for LITHIUM-ION BATTERY): REMOVAL 2022 MY Avalon HV [08/2021 -        ]; HYBRID / BATTERY CONTROL: HV BATTERY STACK (for LITHIUM-ION BATTERY): REMOVAL

B

REPLACE BATTERY ECU ASSEMBLY 2021 MY Avalon HV [08/2020 - 08/2021]; HYBRID / BATTERY CONTROL: BATTERY ECU (for LITHIUM-ION BATTERY): REMOVAL 2022 MY Avalon HV [08/2021 -        ]; HYBRID / BATTERY CONTROL: BATTERY ECU (for LITHIUM-ION BATTERY): REMOVAL