Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001A0EI
Model Year Start: 2019 Model: Avalon HV Prod Date Range: [04/2018 - 08/2020]
Title: HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): P0A9B1C,P0AC51C,P0ACA1C; Hybrid/EV Battery Temperature Sensor "A" Voltage Out of Range; 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]

DTC

P0A9B1C

Hybrid/EV Battery Temperature Sensor "A" Voltage Out of Range

DTC

P0AC51C

Hybrid/EV Battery Temperature Sensor "B" Voltage Out of Range

DTC

P0ACA1C

Hybrid/EV Battery Temperature Sensor "C" Voltage Out of Range

DESCRIPTION

These DTCs will be stored if the difference between the maximum and minimum output of each battery temperature sensors exceeds a certain amount and if the output of one battery temperature sensor deviates from that of the other sensors.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P0A9B1C

Hybrid/EV Battery Temperature Sensor "A" Voltage Out of Range

The performance of battery temperature sensor 0 is abnormal; the difference in output between it and other battery temperature sensors is excessively large.

(1 trip detection logic)

  • Battery voltage sensor
  • Hybrid battery thermistor
  • Wire harness or connector

Comes on

Master Warning Light:

Comes on

P0AC51C

Hybrid/EV Battery Temperature Sensor "B" Voltage Out of Range

The performance of battery temperature sensor 1 is abnormal; the difference in output between it and other battery temperature sensors is excessively large.

(1 trip detection logic)

  • Battery voltage sensor
  • Hybrid battery thermistor
  • Wire harness or connector

Comes on

Master Warning Light:

Comes on

P0ACA1C

Hybrid/EV Battery Temperature Sensor "C" Voltage Out of Range

The performance of battery temperature sensor 2 is abnormal; the difference in output between it and other battery temperature sensors is excessively large.

(1 trip detection logic)

  • Battery voltage sensor
  • Hybrid battery thermistor
  • Wire harness or connector

Comes on

Master Warning Light:

Comes on

Related Data List

DTC No.

Data List

P0A9B1C

  • Hybrid Battery Temperature 1 to 3

P0AC51C

P0ACA1C

HINT:

If the vehicle as is left as is for 24 hours, the value of "Hybrid Battery Temperature" will be almost the same as the ambient temperature.

The following items can be helpful when performing repairs:

Data List

  • Vehicle Speed
  • Ambient Temperature

MONITOR DESCRIPTION

The battery temperature sensors are provided at 3 locations on the bottom of the HV battery. The resistance of the thermistor, which is built into each battery temperature sensor, varies in accordance with changes in the HV battery temperature. The lower the battery temperature, the higher the thermistor resistance. Conversely, the higher the temperature, the lower the resistance. The battery voltage sensor uses the battery temperature sensor to detect the HV battery temperature, and sends the detected value to the hybrid vehicle control ECU. Based on the results of this detection, the hybrid vehicle control ECU controls the blower fan. (The blower fan starts when the HV battery temperature rises above a predetermined level.)

MONITOR STRATEGY

Related DTCs

P0A9C (INF P0A9B1C), P0AC6 (INF P0AC51C), P0ACB (INF P0ACA1C): Battery temperature sensor malfunction (deviation)

Required sensors/components

Battery temperature sensor

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

Battery voltage sensor

DTC P0A9C (INF P0A9B1C) is not detected

DTC P0AC6 (INF P0AC51C) is not detected

DTC P0ACB (INF P0ACA1C) 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 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): UTILITY

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

    Click here 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE 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 / 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 DTC P0A9B2A.

Click here 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): P0A9B2A,P0AC52A,P0ACA2A,P306562; Hybrid/EV Battery Temperature Sensor "A" Signal Stuck In Range+

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 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): PRECAUTION

    *a

    Without waiting for 10 minutes

    HINT:

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

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)

(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) Check for DTCs.

Powertrain > Hybrid Control > Trouble Codes

Result

Proceed to

P0AFC00 or P0AFC96 is not output.

A

P0AFC00 or P0AFC96 is output.

B

(e) Turn the power switch off.

B

GO TO DTC CHART (HYBRID CONTROL SYSTEM)

A

2.

CHECK INSTALLATION OF TEMPERATURE SENSOR (HYBRID BATTERY TEMPERATURE SENSOR)

Click here 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): P0A9B2A,P0AC52A,P0ACA2A,P306562; Hybrid/EV Battery Temperature Sensor "A" Signal Stuck In Range+

Result

Proceed to

Each battery temperature sensor is installed in the correct location with the correct orientation and its claws are engaged securely.

A

Claws are damaged.

B

Any of battery temperature sensors are not installed correctly, but claws are not damaged.

C

B

REPLACE HYBRID BATTERY THERMISTOR

C

INSTALL PARTS CORRECTLY

A

3.

CHECK HV BATTERY (BATTERY TEMPERATURE SENSOR)

Click here 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): P0A9B2A,P0AC52A,P0ACA2A,P306562; Hybrid/EV Battery Temperature Sensor "A" Signal Stuck In Range+

OK

REPLACE BATTERY VOLTAGE SENSOR

NG

4.

CHECK HARNESS AND CONNECTOR (BATTERY TEMPERATURE SENSOR)

Click here 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): P0A9B11,...,P0ACA15; Hybrid/EV Battery Temperature Sensor "A" Circuit Short to Ground+

OK

REPLACE HYBRID BATTERY THERMISTOR

NG

REPAIR HARNESS OR CONNECTOR (BATTERY TEMPERATURE SENSOR)