Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001RITC
Model Year Start: 2021 Model: Avalon HV Prod Date Range: [08/2020 -           ]
Title: HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY): P31B300; Hybrid/EV Battery Voltage High; 2021 - 2022 MY Avalon HV [08/2020 -        ]

DTC

P31B300

Hybrid/EV Battery Voltage High

DTC SUMMARY

MALFUNCTION DESCRIPTION

The hybrid vehicle control ECU uses the inverter voltage to monitor the HV battery voltage and detect malfunctions.

The cause of this malfunction may be the following:

Inverter with converter assembly malfunction (Boost converter system)

  • VL sensor malfunction
  • VH sensor malfunction

HV battery system

  • Battery ECU assembly malfunction
  • HV battery malfunction

DESCRIPTION

The hybrid vehicle control ECU uses the inverter voltage to monitor the HV battery voltage and detect malfunctions.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P31B300

Hybrid/EV Battery Voltage High

The inverter voltage exceeds the threshold.

(1 trip detection logic)

  • Inverter with converter assembly
  • Battery ECU assembly
  • No. 1 HV supply stack sub-assembly
  • No. 2 HV supply stack sub-assembly

Comes on

Master Warning Light:

Comes on

MONITOR DESCRIPTION

The hybrid vehicle control ECU monitors the cell overcharge signal. If the hybrid vehicle control ECU detects an abnormality in the sensor signal, the hybrid vehicle control ECU will illuminate the MIL and set a DTC.

MONITOR STRATEGY

Related DTCs

P31B3 (INF P31B300): Hybrid/EV Battery Voltage high

Required sensors/components

Battery ECU assembly

Frequency of operation

Continuous

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

P31B3 (INF P31B300) 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 CONTROL 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 CONTROL 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. Turn the power switch on (READY) and wait for 30 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.

WIRING DIAGRAM

Refer to the wiring diagram for the HV battery high-voltage line circuit.

Click here 2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY): HV Battery High-voltage Line Circuit+

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 CONTROL SYSTEM (for LITHIUM-ION BATTERY): PRECAUTION 2022 MY Avalon HV [08/2021 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL 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

  • 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 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; INTRODUCTION: REPAIR INSTRUCTION: PRECAUTION

PROCEDURE

1.

CHECK DTC OUTPUT (HYBRID CONTROL, MOTOR GENERATOR)

(a) Connect the Techstream to the DLC3.

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

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

(d) Check for DTCs.

Powertrain > Hybrid Control > Trouble Codes

Powertrain > Motor Generator > Trouble Codes

Result

Proceed to

P31B300 only is output, or DTCs except the ones in the table below are also output.

A

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

B

DTCs of motor generator control system in the tables below are output.

C

Malfunction Content

System

Relevant DTC

Sensor and actuator circuit malfunction

Hybrid control system

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

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

P0D2D1F

Drive Motor "A" Inverter Voltage Sensor(VH) Circuit Intermittent

P0E3116

DC/DC Converter Voltage Sensor "A" (VL) Circuit Voltage Below Threshold

P0E3117

DC/DC Converter Voltage Sensor "A" (VL) Circuit Voltage Above Threshold

P0E311F

DC/DC Converter Voltage Sensor "A"(VL) Circuit Intermittent

P0E5717

DC/DC Converter Voltage Sensor "A"(VL) Circuit Voltage Above Threshold

HINT:

  • P31B300 may be output as a result of the malfunction indicated by the DTCs above.
    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.)

(e) Turn the power switch off.

B

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

C

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

A

2.

READ VALUE USING TECHSTREAM (HYBRID/EV BATTERY VOLTAGE)

(a) Connect the Techstream to the DLC3.

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

(c) Enter the following menus: Powertrain / HV battery / Data List / Hybrid/EV Battery Voltage

(d) Read the Data List.

Powertrain > HV Battery > Data List

Tester Display

Hybrid/EV Battery Voltage

NOTICE:

Be sure not to measure when the power switch is on (READY).

(e) Make a note of the data list item "Hybrid/EV Battery Voltage".

(f) Turn the power switch off.

NEXT

3.

CHECK HV BATTERY

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 power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Remove the electric vehicle battery plug assembly.

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

(c) Disconnect the y10 and y13 HV battery high voltage connectors.

NOTICE:

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

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

Standard Voltage:

Tester Connection

Condition

y10-1 - y13-1

Power switch off

CAUTION:

Do not allow the probes of the electrical tester to contact each other during this inspection.

*a

No. 2 HV Supply Stack Sub-assembly Connector

(Hybrid Battery Terminal Block Side)

*b

No. 1 HV Supply Stack Sub-assembly Connector

(HV Battery Junction Block Assembly Side)

(e) Check the value in the data list "Hybrid/EV Battery Voltage" and the hybrid battery voltage value that was actually measured.

Result

Proceed to

When the difference between "Hybrid/EV Battery Voltage" in the Data List and the measurement value of the HV battery voltage is 5 V or more.

A

Other than above

B

(f) Reconnect the y10 and y13 HV battery high voltage connectors.

(g) Install the electric vehicle battery plug assembly.

B

GO TO STEP 5

A

4.

REPLACE BATTERY ECU ASSEMBLY

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

NEXT

REPLACE NO. 1 HV SUPPLY STACK SUB-ASSEMBLY AND 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

5.

CHECK FREEZE FRAME DATA (HYBRID CONTROL)

(a) Connect the Techstream to the DLC3.

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

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

(d) Read the freeze frame data of DTC P31B300.

Powertrain > Hybrid Control > Trouble Codes

Result

Proceed to

"Hybrid/EV Battery Voltage" is less than 292 V.

A

Other than above

B

(e) Turn the power switch off.

A

REPLACE INVERTER WITH CONVERTER ASSEMBLY 2021 MY Avalon HV [08/2020 - 08/2021]; HYBRID / BATTERY CONTROL: INVERTER WITH CONVERTER: REMOVAL 2022 MY Avalon HV [08/2021 -        ]; HYBRID / BATTERY CONTROL: INVERTER WITH CONVERTER: REMOVAL

B

6.

REPLACE BATTERY ECU ASSEMBLY

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

NEXT

REPLACE NO. 1 HV SUPPLY STACK SUB-ASSEMBLY AND 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