HYBRID CONTROL SYSTEM, Diagnostic DTC:P1AC000

DTC Code DTC Name
P1AC000 Hybrid/EV Battery Cell Low Voltage

DESCRIPTION

The hybrid vehicle control ECU controls the SOC (state of charge) of the HV battery at a constant level during driving. The HV battery is composed of 28 modules, and each module consists of six 1.2 V cells in series. The battery voltage sensor monitors battery block voltage at 9 locations.

B004QMGE01
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 9 Voltage*1

  • Hybrid Battery SOC

Tech Tips


  • *1: Under normal conditions, the values of Hybrid Battery Block 1, 2, 8 and 9 Voltage will be approximately 16 V and Hybrid Battery Block 3, 4, 5, 6 and 7 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:



Tech Tips


  • 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 or 8 and 9 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 Hybrid Battery Cooling Parts at Your Dealer" 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.

CONFIRMATION DRIVING PATTERN

Tech Tips

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


  1. Connect the GTS to the DLC3.

  2. Turn the power switch on (IG) and turn the GTS 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 GTS on.

  6. Drive the vehicle on urban roads for approximately 10 minutes.

    Tech Tips

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

  7. Enter the following menus: Powertrain / Hybrid Control / Utility / All Readiness.

  8. Check the DTC judgment result.

    Tech Tips


    • 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.

CAUTION / NOTICE / HINT

CAUTION:

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.

PROCEDURE


  1. CHECK DTC OUTPUT (HYBRID CONTROL)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.


      Powertrain > Hybrid Control > Trouble Codes

    4. Check for DTCs.

      Result
      Result Proceed to
      P0AFC00, P0AFC96, P308A12 or P0AFC62 is output A
      Other than above B

    5. Turn the power switch off.


    A

    GO TO DTC CHART (HYBRID CONTROL SYSTEM) Click here

    B

  2. CHECK FREEZE FRAME DATA


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Using the GTS, make a note of the freeze frame data item "Hybrid Battery Block (3 to 7) Voltage".


      Powertrain > Hybrid Control > DTC(P1AC000) > Freeze Frame Data
      Tester Display
      Hybrid Battery Block 3 Voltage
      Hybrid Battery Block 4 Voltage
      Hybrid Battery Block 5 Voltage
      Hybrid Battery Block 6 Voltage
      Hybrid Battery Block 7 Voltage

    4. Compare the freeze frame data item "Hybrid Battery Block (3 to 7) 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
      B004PB7C02
      *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 - -
      Result
      Result Proceed to
      On the HV battery blocks 3 to 7, one of the conditions in the table above is met. A
      Other than above B

    5. Turn the power switch off.


    B

    CHECK FREEZE FRAME DATA Click here

    A

  3. CHECK TOTAL DISTANCE DRIVEN


    1. Read the odometer to check the total distance the vehicle has been driven.

      Result
      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

      Tech Tips

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


    A

    REPLACE HV BATTERY Click here

    B

  4. REPLACE HV BATTERY

    Tech Tips

    Click here

    Result
    Proceed to
    NEXT

    NEXT

    REPLACE HYBRID BATTERY TERMINAL BLOCK Click here

  5. CHECK FREEZE FRAME DATA


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Using the GTS, make a note of the freeze frame data item "Hybrid Battery Block 1, 2, 8 and 9 Voltage".


      Powertrain > Hybrid Control > DTC(P1AC000) > Freeze Frame Data
      Tester Display
      Hybrid Battery Block 1 Voltage
      Hybrid Battery Block 2 Voltage
      Hybrid Battery Block 8 Voltage
      Hybrid Battery Block 9 Voltage

    4. Compare the freeze frame data item "Hybrid Battery Block 1, 2, 8 and 9 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 8 Voltage Hybrid Battery Block 9 Voltage "Hybrid Battery Block 8 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 8 Voltage Hybrid Battery Block 9 Voltage "Hybrid Battery Block 9 Voltage" - "Hybrid Battery Block 8 Voltage" = 1.2 V or more
      B004OTAC02
      *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 - -

      Tech Tips

      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
      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

    5. Turn the power switch off.


    A

    REPLACE BATTERY VOLTAGE SENSOR Click here

    B

  6. CHECK TOTAL DISTANCE DRIVEN


    1. Read the odometer to check the total distance the vehicle has been driven.

      Result
      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

      Tech Tips

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


    A

    REPLACE HV BATTERY Click here

    B

  7. REPLACE HV BATTERY

    Tech Tips

    Click here

    Result
    Proceed to
    NEXT

    NEXT

    REPLACE HYBRID BATTERY TERMINAL BLOCK Click here