Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Hybrid/EV Battery Stack 1 Delta SOC High (P1A8000,P1AD01B)

DESCRIPTION

The battery voltage sensor and the hybrid vehicle control ECU calculate the SOC (state of charge) of the HV battery through the accumulated amperage in the HV battery. The battery voltage sensor sends the condition of the HV battery to the hybrid vehicle control ECU. Then the hybrid vehicle control ECU calculates the SOC based on the information and controls the charging and discharging of the HV battery based to the driving condition.

Based on the HV battery voltage and current, the battery voltage sensor calculates the resistance and judges if the HV battery has deteriorated.

HINT:

• *1: Under normal conditions, the values of Hybrid Battery Block 1, 2, 9, 10 and 11 Voltage will be approximately 16 V and Hybrid Battery Block 3, 4, 5, 6, 7 and 8 Voltage will be approximately 32 V.
• If there is a short or open in a battery block voltage detection line, the value of Hybrid Battery Block Voltage for the corresponding battery block will be lower than 8 V.

The following items can be helpful when performing repairs:

• Ready Signal
• Vehicle Speed
• Accelerator Position
• Shift Position
• Engine Speed
• Hybrid Battery Voltage
• Hybrid Battery Current
• BATT Voltage
• Hybrid Battery SOC just after IG-ON
• Hybrid Battery Maximum SOC
• Hybrid Battery Minimum SOC
• Total Distance Traveled
• Distance from DTC Cleared
• Engine Run Time
• Number of Battery Current Sensor Characteristics Determination

• Hybrid Battery Voltage Low

HINT:

• This DTC can be stored after clearing DTCs and driving the vehicle for approximately 10 minutes. (As 2 trip detection logic is also used, check for DTCs including pending DTCs.)
• This DTC may not be stored if the vehicle is stopped or being driven at a steady speed.
• When the internal resistance of the HV battery increases, battery block voltage may drop.
• If resistance is abnormal, the voltage of the battery blocks indicated by the DTCs are likely to decrease more than others during acceleration (discharging), and increase more during deceleration (charging).
• In order to ensure HV battery performance, appropriate cooling performance must be maintained. Perform the following items as necessary. If cooling performance has decreased and "Maintenance Required for Traction Battery Cooling Parts See Owner's Manual" is displayed on the multi-information display, make sure to perform the following items:
  • Make sure the air intake port is not blocked.
  • Make sure there are no gaps between the connecting parts of the ducts.
  • Clean the No. 1 HV battery intake filter.
    • Clear the DTCs to reset the learning values even if no DTCs are stored.

MONITOR DESCRIPTION

If there is an abnormal internal resistance or SOC in the battery blocks, the battery voltage sensor determines that a malfunction has occurred. When the malfunction detection condition is satisfied, the hybrid vehicle control ECU will illuminate the MIL and store a DTC.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

COMPONENT OPERATING RANGE

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.

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

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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. Drive the vehicle on urban roads at a speed of 40 km/h (25 mph) or more for a total of at least 10 minutes. (It is not necessary to maintain the vehicle speed at 40 km/h (25 mph) throughout the road test.)[*1]

   HINT:

   • This DTC may not be stored if the vehicle is stopped or being driven at a steady speed.
   • [*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.

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

• 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.
• 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.

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PROCEDURE

(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 and record any HV system DTCs and freeze frame data.

(e) Turn the power switch off.

B

GO TO DTC CHART (HYBRID CONTROL SYSTEM)

A

(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) Using the Techstream, make a note of the freeze frame data item "Number of Hybrid Battery Current Sensor Characteristics Determination".

(e) Turn the power switch off.

(f) Disconnect the Techstream from the DLC3.

B

REPLACE HV BATTERY JUNCTION BLOCK ASSEMBLY

A

(a) Read the odometer to check the total distance the vehicle has been driven.

HINT:

*1: If the hybrid battery terminal block has been replaced, use the total distance driven since it was replaced.

A

REPLACE HV BATTERY

B

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NEXT

REPLACE HYBRID BATTERY TERMINAL BLOCK