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

The battery temperature sensors are provided at 6 locations 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 ECU assembly uses the battery temperature sensors to detect the HV battery temperature. Based on the results of this detection, the battery ECU assembly controls the blower fan. (The blower fan starts when the HV battery temperature rises above a predetermined level.)

Use the reference table above to determine which battery temperature sensor corresponds to each DTC. For example, sensor A in the DTC title column is battery temperature sensor 0. This sensor is displayed as Hybrid/EV Battery Temperature 1 in the Data List.

Related Data List

HINT:

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

Temperature Displayed	Malfunction
Below -45°C (-49°F)	Open or +B short circuit
95°C (203°F) or more	GND short circuit

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

MONITOR DESCRIPTION

If the battery ECU assembly detects a malfunction in a HV battery temperature sensor, the battery ECU will illuminate the MIL and store a DTC.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

COMPONENT OPERATING RANGE

CONFIRMATION DRIVING PATTERN

Connect the Techstream to the DLC3.
Turn the power switch on (IG) and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the power switch off and wait for 2 minutes or more.
Turn the power switch on (IG) and turn the Techstream on.
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.
Enter the following menus: Powertrain / HV Battery / Utility / All Readiness.
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.

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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

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

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.

PROCEDURE

Powertrain > HV Battery > Trouble Codes

Powertrain > Hybrid Control > Trouble Codes

Powertrain > HV Battery > Data List

A malfunctioning sensor (battery temperature sensor 0, 1, 2, 3, or 5) can be determined by comparing the output temperature of the 6 battery temperature sensors.

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.

(a) Check the DTCs that were output when the vehicle was brought to the workshop.

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.

(i) Reconnect the y12 battery current sensor connector to the HV battery junction block assembly.

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.

(f) Reconnect the y12 battery current sensor connector to the HV battery junction block assembly.

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.