Last Modified: 11-20-2023 6.11:8.1.0 Doc ID: RM1000000014UF3
Model Year Start: 2018 Model: Camry HV Prod Date Range: [07/2017 -           ]
Title: HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): P1AC000; Hybrid/EV Battery Cell Low Voltage; 2018 - 2024 MY Camry HV [07/2017 -        ]

DTC

P1AC000

Hybrid/EV Battery Cell Low Voltage

DESCRIPTION

The hybrid vehicle control ECU assembly controls the SOC (state of charge) of the HV battery at a constant level during driving. The HV battery is composed of 34 modules, and each module consists of six 1.2 V cells in series. The battery voltage sensor monitors battery block voltage at 11 locations.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P1AC000

Hybrid/EV Battery Cell Low Voltage

Voltage difference between battery blocks is larger than the specified value due to an internal malfunction of the HV battery.

(2 trip detection logic)

  • Battery voltage sensor
  • HV battery
  • Hybrid battery terminal block

Comes on

Master Warning Light:

Comes on

Related Data List

DTC No.

Data List

P1AC000

  • Hybrid Battery Block 1 to 11 Voltage*1
  • Hybrid Battery SOC

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:

Data List

  • Internal Resistance 1 to 11
  • Ready Signal
  • Vehicle Speed
  • Accelerator Position
  • Shift Position
  • Engine Speed
  • Hybrid Battery Voltage
  • Hybrid Battery Current
  • BATT Voltage
  • Hybrid Battery SOC of Immediately after IG ON
  • Hybrid Battery Maximum SOC
  • Hybrid Battery Minimum SOC
  • Total Distance Traveled
  • Distance from DTC Cleared
  • Engine Run Time

Vehicle Control History Data

  • 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 used, check for DTCs including pending DTCs.)
  • DTC P1AC000 is stored when a malfunction is detected in the HV battery or battery voltage sensor. If the HV battery is malfunctioning, the malfunction may not be reproduced when the condition of the HV battery changes due to a difference in driving load (amperage), battery SOC and battery temperature. Therefore, use the freeze frame data when performing a repair.
    1. When the HV battery is malfunctioning:
      • - Voltage of 1 or few battery blocks has dropped. The difference of voltage value between the hybrid battery block 1 and 2, 3 and 4, 4 and 5, 5 and 6, 6 and 7, 7 and 8, 9 and 10 or 10 and 11 is 1.2 V or more.
      • - Voltage of all battery blocks is output randomly with no certain pattern.
    2. When the battery voltage sensor is malfunctioning:
      • - Differences in battery block voltages have a certain pattern.
  • 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

The battery voltage sensor, which monitors the voltage of the battery blocks, determines that a malfunction has occurred if a voltage difference between the battery blocks exceeds the standard. When the malfunction detection condition is satisfied, the hybrid vehicle control ECU assembly will illuminate the MIL and store a DTC.

MONITOR STRATEGY

Related DTCs

P1AC0 (INF P1AC000): Battery cell malfunction

Required sensors/components

Main: Battery voltage sensor

Sub: Battery current sensor, battery temperature sensor

Frequency of operation

Continuous

Duration

TMC's intellectual property

MIL operation

2 driving cycles

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 P1AC0 (INF P1AC000) 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 2018 - 2024 MY Camry HV [07/2017 -        ]; 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 2018 - 2022 MY Camry HV [07/2017 - 08/2022]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): DTC CHECK / CLEAR 2023 - 2024 MY Camry HV [08/2022 -        ]; 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. Drive the vehicle on urban roads for approximately 10 minutes.[*1]

    HINT:

    • This DTC may not be stored if the vehicle is stopped or being driven at a constant 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.

    Click here 2018 - 2020 MY Camry HV [07/2017 - 10/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): PRECAUTION 2021 - 2024 MY Camry HV [10/2020 -        ]; 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.

  • 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.

Click here 2018 - 2019 MY Camry HV [07/2017 - 09/2019]; INTRODUCTION: REPAIR INSTRUCTION: PRECAUTION 2020 - 2024 MY Camry HV [09/2019 -        ]; 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, P0AFC96, P308A12 or P0AFC62" is not output.

A

"P0AFC00, P0AFC96, P308A12 or P0AFC62" is also output.

B

(e) Turn the power switch off.

B

GO TO DTC CHART (HYBRID CONTROL SYSTEM) 2018 MY Camry HV [07/2017 - 09/2018]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): DIAGNOSTIC TROUBLE CODE CHART 2019 - 2020 MY Camry HV [09/2018 - 10/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): DIAGNOSTIC TROUBLE CODE CHART 2021 - 2024 MY Camry HV [10/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): DIAGNOSTIC TROUBLE CODE CHART

A

2.

CHECK FREEZE FRAME DATA

(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) Read output DTCs.

Powertrain > Hybrid Control > Trouble Codes

(e) Using the Techstream, make a note of the freeze frame data item "Hybrid Battery Block 3 to 8 Voltage".

(f) Compare the freeze frame data item "Hybrid Battery Block 3 to 8 Voltage" values with those shown in the following combination tables.

Condition

"Hybrid Battery Block 3 Voltage" - "Hybrid Battery Block 4 Voltage" = 1.2 V or more

"Hybrid Battery Block 4 Voltage" - "Hybrid Battery Block 3 Voltage" = 1.2 V or more

"Hybrid Battery Block 4 Voltage" - "Hybrid Battery Block 5 Voltage" = 1.2 V or more

"Hybrid Battery Block 5 Voltage" - "Hybrid Battery Block 4 Voltage" = 1.2 V or more

"Hybrid Battery Block 5 Voltage" - "Hybrid Battery Block 6 Voltage" = 1.2 V or more

"Hybrid Battery Block 6 Voltage" - "Hybrid Battery Block 5 Voltage" = 1.2 V or more

"Hybrid Battery Block 6 Voltage" - "Hybrid Battery Block 7 Voltage" = 1.2 V or more

"Hybrid Battery Block 7 Voltage" - "Hybrid Battery Block 6 Voltage" = 1.2 V or more

"Hybrid Battery Block 7 Voltage" - "Hybrid Battery Block 8 Voltage" = 1.2 V or more

"Hybrid Battery Block 8 Voltage" - "Hybrid Battery Block 7 Voltage" = 1.2 V or more

*a

Hybrid Battery Block 1 Voltage

*b

Hybrid Battery Block 2 Voltage

*c

Hybrid Battery Block 3 Voltage

*d

Hybrid Battery Block 4 Voltage

*e

Hybrid Battery Block 5 Voltage

*f

Hybrid Battery Block 6 Voltage

*g

Hybrid Battery Block 7 Voltage

*h

Hybrid Battery Block 8 Voltage

*i

Hybrid Battery Block 9 Voltage

*j

Hybrid Battery Block 10 Voltage

*k

Hybrid Battery Block 11 Voltage

-

-

Result

Proceed to

On the HV battery blocks 3 to 8, one of the conditions in the table above is met.

A

Other than above

B

(g) Turn the power switch off.

B

GO TO STEP 5

A

3.

CHECK TOTAL DISTANCE DRIVEN

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

Result

Proceed to

Total distance driven is less than 200000 km (124280 mile)

A

Total distance driven is 200000 km (124280 mile) or more

Current total distance driven - total distance driven when hybrid battery terminal block replaced = less than 200000 km (124280 mile) *1

Other than above

B

HINT:

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

A

REPLACE HV BATTERY 2018 - 2020 MY Camry HV [07/2017 - 10/2020]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL 2021 - 2024 MY Camry HV [10/2020 -        ]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL

B

4.

REPLACE HV BATTERY

Click here 2018 - 2020 MY Camry HV [07/2017 - 10/2020]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL 2021 - 2024 MY Camry HV [10/2020 -        ]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL

NEXT

REPLACE HYBRID BATTERY TERMINAL BLOCK 2018 - 2020 MY Camry HV [07/2017 - 10/2020]; HYBRID / BATTERY CONTROL: FUSE BOX(for NICKEL METAL HYDRIDE BATTERY): REMOVAL 2021 - 2024 MY Camry HV [10/2020 -        ]; HYBRID / BATTERY CONTROL: FUSE BOX(for NICKEL METAL HYDRIDE BATTERY): REMOVAL

5.

CHECK FREEZE FRAME DATA

(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) Read output DTCs.

Powertrain > Hybrid Control > Trouble Codes

(e) Using the Techstream, make a note of the freeze frame data item "Hybrid Battery Block 1, 2, 9, 10 and 11 Voltage".

(f) Compare the freeze frame data item "Hybrid Battery Block 1, 2, 9, 10 and 11 Voltage" values with those shown in the following combination tables.

Table 1

Circuit A Battery Block

Circuit B Battery Block

Condition

Hybrid Battery Block 1 Voltage

Hybrid Battery Block 2 Voltage

"Hybrid Battery Block 1 Voltage" - "Hybrid Battery Block 2 Voltage" = 1.2 V or more

Hybrid Battery Block 10 Voltage

Hybrid Battery Block 9 Voltage

"Hybrid Battery Block 10 Voltage" - "Hybrid Battery Block 9 Voltage" = 1.2 V or more

Hybrid Battery Block 11 Voltage

Hybrid Battery Block 9 Voltage

"Hybrid Battery Block 11 Voltage" - "Hybrid Battery Block 9 Voltage" = 1.2 V or more

Table 2

Circuit A Battery Block

Circuit B Battery Block

Condition

Hybrid Battery Block 1 Voltage

Hybrid Battery Block 2 Voltage

"Hybrid Battery Block 2 Voltage" - "Hybrid Battery Block 1 Voltage" = 1.2 V or more

Hybrid Battery Block 10 Voltage

Hybrid Battery Block 9 Voltage

"Hybrid Battery Block 9 Voltage" - "Hybrid Battery Block 10 Voltage" = 1.2 V or more

Hybrid Battery Block 11 Voltage

Hybrid Battery Block 9 Voltage

"Hybrid Battery Block 9 Voltage" - "Hybrid Battery Block 11 Voltage" = 1.2 V or more

*a

Hybrid Battery Block 1 Voltage

*b

Hybrid Battery Block 2 Voltage

*c

Hybrid Battery Block 3 Voltage

*d

Hybrid Battery Block 4 Voltage

*e

Hybrid Battery Block 5 Voltage

*f

Hybrid Battery Block 6 Voltage

*g

Hybrid Battery Block 7 Voltage

*h

Hybrid Battery Block 8 Voltage

*i

Hybrid Battery Block 9 Voltage

*j

Hybrid Battery Block 10 Voltage

*k

Hybrid Battery Block 11 Voltage

-

-

HINT:

If an internal malfunction occurs in the battery voltage sensor, this symptom (difference in voltage of 1.2 V or more for certain pairs of blocks as shown in the illustration) will occur.

Result

Proceed to

Either of the following conditions is met:

1. All conditions in table 1 are met.

2. All conditions in table 2 are met.

A

Other than above

B

(g) Turn the power switch off.

A

REPLACE BATTERY VOLTAGE SENSOR 2018 - 2020 MY Camry HV [07/2017 - 10/2020]; HYBRID / BATTERY CONTROL: BATTERY VOLTAGE SENSOR(for NICKEL METAL HYDRIDE BATTERY): REMOVAL 2021 - 2024 MY Camry HV [10/2020 -        ]; HYBRID / BATTERY CONTROL: BATTERY VOLTAGE SENSOR(for NICKEL METAL HYDRIDE BATTERY): REMOVAL

B

6.

CHECK TOTAL DISTANCE DRIVEN

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

Result

Proceed to

Total distance driven is less than 200000 km (124280 mile)

A

Total distance driven is 200000 km (124280 mile) or more

Current total distance driven - total distance driven when hybrid battery terminal block replaced = less than 200000 km (124280 mile) *1

Other than above

B

HINT:

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

A

REPLACE HV BATTERY 2018 - 2020 MY Camry HV [07/2017 - 10/2020]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL 2021 - 2024 MY Camry HV [10/2020 -        ]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL

B

7.

REPLACE HV BATTERY

Click here 2018 - 2020 MY Camry HV [07/2017 - 10/2020]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL 2021 - 2024 MY Camry HV [10/2020 -        ]; HYBRID / BATTERY CONTROL: HV BATTERY (for NICKEL METAL HYDRIDE BATTERY): REMOVAL

NEXT

REPLACE HYBRID BATTERY TERMINAL BLOCK 2018 - 2020 MY Camry HV [07/2017 - 10/2020]; HYBRID / BATTERY CONTROL: FUSE BOX(for NICKEL METAL HYDRIDE BATTERY): REMOVAL 2021 - 2024 MY Camry HV [10/2020 -        ]; HYBRID / BATTERY CONTROL: FUSE BOX(for NICKEL METAL HYDRIDE BATTERY): REMOVAL