Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001B4CL
Model Year Start: 2019 Model: Avalon HV Prod Date Range: [04/2018 -           ]
Title: A25A-FXS (ENGINE CONTROL): SFI SYSTEM: P056014; System Voltage Circuit Short to Ground or Open; 2019 - 2022 MY Avalon HV [04/2018 -        ]

DTC

P056014

System Voltage Circuit Short to Ground or Open

MONITOR DESCRIPTION

The auxiliary battery supplies electricity to the ECM even when the power switch is off. This power allows the ECM to store data such as DTC history, Freeze Frame Data and fuel trim values. If the auxiliary battery voltage falls below a minimum level, the memory is cleared and the ECM determines that there is a malfunction in the power supply circuit. The ECM will illuminate the MIL and store this DTC.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

Note

P056014

System Voltage Circuit Short to Ground or Open

An open or short in the ECM backup power source circuit (1 trip detection logic).
  • Open or short in back up power source circuit
  • Auxiliary battery
  • Auxiliary battery terminals
  • ECM

Comes on

DTC stored

SAE Code: P0562

MONITOR STRATEGY

Related DTCs

P0562: ECM system voltage range check (low voltage)

Required Sensors/Components (Main)

ECM

Required Sensors/Components (Related)

-

Frequency of Operation

Continuous

Duration

3 seconds

MIL Operation

Immediate

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever the following DTCs are not stored

None

Both of the following conditions are met

-

Auxiliary battery voltage

8 V or higher

Power switch

On (IG)

TYPICAL MALFUNCTION THRESHOLDS

Continuous auxiliary battery voltage

Less than 3.5 V

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 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR

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

    Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR

  1. Connect the Techstream to the DLC3.
  2. Turn the power switch on (IG).
  3. Turn the Techstream on.
  4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  5. Turn the power switch off and wait for at least 30 seconds.
  6. Turn the power switch on (IG).
  7. Turn the Techstream on.
  8. Wait 5 seconds or more [A].
  9. Enter the following menus: Powertrain / Engine / Trouble Codes [B].
  10. Read the pending DTCs.

    HINT:

    • If a pending DTC is output, the system is malfunctioning.
    • If a pending DTC is not output, perform the following procedure.
  11. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
  12. Input the DTC: P056014.
  13. Check the DTC judgment result.

    Techstream Display

    Description

    NORMAL
    • DTC judgment completed
    • System normal

    ABNORMAL
    • DTC judgment completed
    • System abnormal

    INCOMPLETE
    • DTC judgment not completed
    • Perform driving pattern after confirming DTC enabling conditions

    HINT:

    • If the judgment result is NORMAL, the system is normal.
    • If the judgment result is ABNORMAL, the system is malfunctioning.
    • [A] to [B]: Normal judgment procedure.

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

    • When clearing the permanent DTCs, do not disconnect the cable from the auxiliary battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Inspect the fuses for circuits related to this system before performing the following procedure.
  • After turning 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

  • Vehicle Control History may be stored in the hybrid vehicle control ECU assembly if the engine is malfunctioning. Certain vehicle condition information is recorded when Vehicle Control History is stored. Reading the vehicle conditions recorded in both the Freeze Frame Data and Vehicle Control History can be useful for troubleshooting.

    Click here 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): VEHICLE CONTROL HISTORY 2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY): VEHICLE CONTROL HISTORY

    (Select Powertrain in Health Check and then check the time stamp data.)

    Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR

  • If any "Engine Malfunction" Vehicle Control History item has been stored in the hybrid vehicle control ECU assembly, make sure to clear it. However, as all Vehicle Control History items are cleared simultaneously, if any Vehicle Control History items other than "Engine Malfunction" are stored, make sure to perform any troubleshooting for them before clearing Vehicle Control History.

    Click here 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): VEHICLE CONTROL HISTORY 2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY): VEHICLE CONTROL HISTORY

HINT:

Read Freeze Frame Data using the Techstream. The ECM records vehicle and driving condition information as Freeze Frame Data the moment a DTC is stored. When troubleshooting, Freeze Frame Data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

1.

INSPECT AUXILIARY BATTERY

(a) Inspect the auxiliary battery.

Click here 2019 - 2021 MY Avalon HV [04/2018 - 08/2021]; A25A-FXS (BATTERY / CHARGING): CHARGING SYSTEM: ON-VEHICLE INSPECTION 2022 MY Avalon HV [08/2021 -        ]; A25A-FXS (BATTERY / CHARGING): CHARGING SYSTEM: ON-VEHICLE INSPECTION

OK:

Auxiliary battery voltage is between 11 to 14 V.

NG

CHARGE OR REPLACE AUXILIARY BATTERY
OK

2.

CHECK AUXILIARY BATTERY TERMINAL

(a) Check that the auxiliary battery terminals are not loose or corroded.

Click here 2019 - 2021 MY Avalon HV [04/2018 - 08/2021]; A25A-FXS (BATTERY / CHARGING): CHARGING SYSTEM: ON-VEHICLE INSPECTION+ 2022 MY Avalon HV [08/2021 -        ]; A25A-FXS (BATTERY / CHARGING): CHARGING SYSTEM: ON-VEHICLE INSPECTION

OK:

Auxiliary battery terminals are not loose or corroded.

NG

REPAIR OR REPLACE AUXILIARY BATTERY TERMINAL
OK

3.

CHECK TERMINAL VOLTAGE (POWER SOURCE OF ECM)

*a

Front view of wire harness connector

(to ECM)

(a) Disconnect the ECM connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A19-1 (BATT) - Body ground

Always

11 to 16 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - ECM)
OK

4.

CLEAR DTC

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(d) Clear the DTCs.

Powertrain > Engine > Clear DTCs

(e) Turn the power switch off and wait for at least 30 seconds.

NEXT

5.

CHECK WHETHER DTC OUTPUT RECURS (DTC P056014)

(a) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(b) Enter the following menus: Powertrain / Engine / Trouble Codes.

(c) Read the DTCs.

Powertrain > Engine > Trouble Codes

Result

Proceed to

DTCs are not output

A

DTC P056014 is output

B
A

CHECK FOR INTERMITTENT PROBLEMS

B

REPLACE ECM 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; A25A-FXS (ENGINE CONTROL): ECM: REMOVAL 2021 MY Avalon HV [08/2020 - 08/2021]; A25A-FXS (ENGINE CONTROL): ECM: REMOVAL 2022 MY Avalon HV [08/2021 -        ]; A25A-FXS (ENGINE CONTROL): ECM: REMOVAL