Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001RK1I
Model Year Start: 2021 Model: Avalon HV Prod Date Range: [08/2020 -           ]
Title: HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): P0AAC11,P0AAC15; Hybrid/EV Battery Air Temperature Sensor "A" Circuit Short to Ground; 2021 - 2022 MY Avalon HV [08/2020 -        ]

DTC

P0AAC11

Hybrid/EV Battery Air Temperature Sensor "A" Circuit Short to Ground

DTC

P0AAC15

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

DESCRIPTION

The inlet air temperature sensor (HV battery) is mounted on the HV battery. The resistance of the sensor varies in accordance with changes in the intake air temperature. The characteristics of the inlet air temperature sensor are the same as those of the battery temperature sensors (Click here 2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): P0A9B11,...,P0C3315; Hybrid/EV Battery Temperature Sensor "A" Circuit Short to Ground+ ). The battery ECU assembly uses signals from the inlet air temperature sensor to control the air volume of the battery cooling blower assembly.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P0AAC11

Hybrid/EV Battery Air Temperature Sensor "A" Circuit Short to Ground

The inlet air temperature sensor output voltage is lower than the specified value (short circuit) and the detected temperature is higher than the specified value.

(1 trip detection logic)

  • No. 1 HV supply stack sub-assembly
  • No. 2 HV supply stack sub-assembly
  • Battery ECU assembly
  • Wire harness or connector

Does not come on

Master Warning Light:

Comes on

P0AAC15

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

The inlet air temperature sensor output voltage is higher than the standard value (short to +B or open) and the detected temperature is lower than the specified value.

(1 trip detection logic)

  • No. 1 HV supply stack sub-assembly
  • No. 2 HV supply stack sub-assembly
  • Battery ECU assembly
  • Wire harness or connector

Does not come on

Master Warning Light:

Comes on

HINT:

After checking for the above DTCs, check the hybrid system Data List item "Hybrid/EV Battery Cooling Fan Intake Air Temperature 1" using the Techstream.

Displayed Temperature

Malfunction

-45°C (-49°F) or less

Open or +B short circuit

95°C (203°F) or more

GND short

Related Data List

DTC No.

Data List

P0AAC11

Hybrid/EV Battery Cooling Fan Intake Air Temperature 1

P0AAC15

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

  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 5 seconds.
  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 driving pattern 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

"P0AAC11 or P0AAC15" 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

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 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.

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

NG

CONNECT SECURELY

OK

3.

CHECK INSTALLATION OF INLET AIR TEMPERATURE SENSOR

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 upper HV battery cover sub-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+

(c) Visually check the installation condition of the inlet air temperature sensor.

Result:

Result

Proceed to

The inlet air temperature sensor is installed in the correct location and its claws are engaged securely.

A

The claws of the inlet air temperature sensor are damaged.

B

The inlet air temperature sensor is not installed correctly, but its claws are not damaged.

C

(d) Install the upper HV battery cover sub-assembly.

B

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

C

INSTALL PARTS CORRECTLY

A

4.

CHECK HV BATTERY (INLET AIR TEMPERATURE SENSOR)

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) Disconnect the y15 battery ECU assembly connector.

NOTICE:

Before disconnecting the connector, check that it is not loose or disconnected.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

y15-22 (TC0) - y15-21 (GC0)

Power switch off

0 to 10°C (32 to 50°F)

17.7 to 27.8 kΩ

y15-22 (TC0) - y15-21 (GC0)

Power switch off

10 to 20°C (50 to 68°F)

12.0 to 18.2 kΩ

y15-22 (TC0) - y15-21 (GC0)

Power switch off

20 to 30°C (68 to 86°F)

8.22 to 12.2 kΩ

y15-22 (TC0) - y15-21 (GC0)

Power switch off

30 to 40°C (86 to 104°F)

5.74 to 8.41 kΩ

y15-22 (TC0) - y15-21 (GC0)

Power switch off

40 to 50°C (104 to 122°F)

4.09 to 5.91 kΩ

NOTICE:

When taking a measurement with a tester, do not apply excessive force to the tester probe to avoid damaging the holder.

*a

Front view of wire harness connector

(to Battery ECU Assembly)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

y15-22 (TC0) - Body ground and other terminals

Power switch off

10 kΩ or higher

y15-21 (GC0) - Body ground and other terminals

Power switch off

10 kΩ or higher

(f) Connect the cable to the negative (-) auxiliary battery terminal.

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

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

y15-22 (TC0) - Body ground

Power switch on (IG)

Below 1 V

y15-21 (GC0) - Body ground

Power switch on (IG)

Below 1 V

NOTICE:

  • Turning the power switch on (IG) with the service plug grip removed causes other DTCs to be stored. Clear the DTCs after performing this inspection.
  • If the power switch is turned on (IG) with the connectors disconnected, other DTCs will be stored. Be sure to clear the DTCs after the inspection.

(i) Turn the power switch off.

(j) Disconnect the cable from the negative (-) auxiliary battery terminal.

(k) Reconnect the y15 battery ECU assembly connector.

(l) Install the No. 1 HV battery hose.

NG

GO TO STEP 9

OK

5.

CHECK BATTERY ECU ASSEMBLY (VIB VOLTAGE)

Click here 2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): P0A9B11,...,P0C3315; Hybrid/EV Battery Temperature Sensor "A" Circuit Short to Ground+

OK

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

NG

6.

CHECK HV BATTERY JUNCTION BLOCK ASSEMBLY (BATTERY CURRENT SENSOR OUTPUT VOLTAGE)

Click here 2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): P0A9B11,...,P0C3315; Hybrid/EV Battery Temperature Sensor "A" Circuit Short to Ground+

OK

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

NG

7.

CHECK HARNESS AND CONNECTOR (NO. 2 HV SUPPLY STACK SUB-ASSEMBLY - HV BATTERY JUNCTION BLOCK ASSEMBLY)

Click here 2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): P0A9B11,...,P0C3315; Hybrid/EV Battery Temperature Sensor "A" Circuit Short to Ground+

NG

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

OK

8.

CHECK HARNESS AND CONNECTOR (BATTERY ECU ASSEMBLY - NO. 1 HV SUPPLY STACK SUB-ASSEMBLY)

Click here 2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): P0A9B11,...,P0C3315; Hybrid/EV Battery Temperature Sensor "A" Circuit Short to Ground+

OK

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

NG

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

9.

CHECK HV BATTERY (INLET AIR TEMPERATURE SENSOR)

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) Disconnect the A No. 2 HV supply stack sub-assembly connector.

NOTICE:

Before disconnecting the connector, check that it is not loose or disconnected.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A-12 (TC0) - A-3 (GC0)

Power switch off

0 to 10°C (32 to 50°F)

17.7 to 27.8 kΩ

A-12 (TC0) - A-3 (GC0)

Power switch off

10 to 20°C (50 to 68°F)

12.0 to 18.2 kΩ

A-12 (TC0) - A-3 (GC0)

Power switch off

20 to 30°C (68 to 86°F)

8.22 to 12.2 kΩ

A-12 (TC0) - A-3 (GC0)

Power switch off

30 to 40°C (86 to 104°F)

5.74 to 8.41 kΩ

A-12 (TC0) - A-3 (GC0)

Power switch off

40 to 50°C (104 to 122°F)

4.09 to 5.91 kΩ

*a

Front view of wire harness connector

(to No. 1 HV Supply Stack Sub-assembly)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A-12 (TC0) - Body ground and other terminals

Power switch off

10 kΩ or higher

A-3 (GC0) - Body ground and other terminals

Power switch off

10 kΩ or higher

(f) Connect the cable to the negative (-) auxiliary battery terminal.

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

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

A-12 (TC0) - Body ground

Power switch on (IG)

Below 1 V

A-3 (GC0) - Body ground

Power switch on (IG)

Below 1 V

NOTICE:

  • Turning the power switch on (IG) with the service plug grip removed causes other DTCs to be stored. Clear the DTCs after performing this inspection.
  • If the power switch is turned on (IG) with the connectors disconnected, other DTCs will be stored. Be sure to clear the DTCs after the inspection.

(i) Turn the power switch off.

(j) Disconnect the cable from the negative (-) auxiliary battery terminal.

(k) Reconnect the A No. 2 HV supply stack sub-assembly connector.

(l) Install the No. 1 HV battery hose.

OK

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

NG

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