Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001N407
Model Year Start: 2021 Model: Corolla Prod Date Range: [04/2020 - 09/2022]
Title: HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with P610): P314A31; Motor Electronics Coolant Pump "A" No Signal; 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]

DTC

P314A31

Motor Electronics Coolant Pump "A" No Signal

DESCRIPTION

Refer to the description for DTC P0C7396.

Click here 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with P610): P0C7396; Motor Electronics Coolant Pump "A" Component Internal Failure+

The inverter water pump assembly sends the inverter water pump speed (measured value) signal to the hybrid vehicle control ECU.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P314A31

Motor Electronics Coolant Pump "A" No Signal

The inverter water pump speed signal is not sent to the hybrid vehicle control ECU when the power switch is turned on (READY).*

(1 trip detection logic)
  • Wire harness or connector
  • Hybrid vehicle control ECU
  • Inverter water pump assembly
  • INV W/PMP fuse
  • IGCT relay
  • IGCT fuse

Comes on

Master Warning: Comes on

*: Either of the following conditions is met.

  • A malfunction (open, short to +B or short to ground) in the speed signal line from the inverter water pump assembly to the hybrid vehicle control ECU is detected.
  • A malfunction in the inverter water pump assembly power source circuit is detected.
  • A malfunction in the +B line is detected.
  • A malfunction in hybrid vehicle control ECU power source circuit is detected.

Related Data List

DTC No.

Data List

P314A31
  • Inverter Water Pump Revolution
  • Inverter Water Pump Duty Ratio
  • Ready Signal

Related Active Test

DTC No.

Active Test

P314A31

Activate the Inverter Water Pump

MONITOR DESCRIPTION

The hybrid vehicle control ECU monitors the speed of the inverter water pump assembly. If the inverter water pump speed signal is not sent to the hybrid vehicle control ECU, the hybrid vehicle control ECU will illuminate the MIL and store a DTC.

MONITOR STRATEGY

Related DTCs

P314A (INF P314A31): Inverter water pump malfunction

Required sensors/components

Inverter Water Pump Assembly

Frequency of operation

Continuous

Duration

TMC's intellectual property

MIL operation

Immediately

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

Hybrid vehicle control ECU

DTC P314A (INF P314A31) 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 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with P610): UTILITY

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

    Click here 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with P610): 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. Turn the power switch on (READY) and wait for 2 minutes 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 P0C7396.

Click here 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with P610): P0C7396; Motor Electronics Coolant Pump "A" Component Internal Failure+

PROCEDURE

1.

CLEAR DTC

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NEXT

2.

PERFORM ACTIVE TEST USING TECHSTREAM (ACTIVATE THE INVERTER WATER PUMP)

NOTICE:

  • Make sure that the HV coolant level is above the low line of the inverter reserve tank.
  • Be sure to perform the inspection with the auxiliary battery voltage at 11 V or more.

HINT:

  • When the auxiliary battery voltage is low, the inverter water pump assembly may not operate.
  • When the inverter water pump assembly signal line (SWP - IWP) is open or its connection is faulty, the inverter water pump assembly is operated forcibly.

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Enter the following menus: Powertrain / Hybrid Control / Active Test / Activate the Inverter Water Pump.

(d) Perform the "Activate the Inverter Water Pump" Active Test.

Powertrain > Hybrid Control > Active Test

Tester Display

Activate the Inverter Water Pump

(e) Touch the inverter water pump assembly and check that it is operating (vibrating).

OK:

The inverter water pump is operating (vibrating).

HINT:

Perform the Active Test with the inverter coolant temperature between -15 and 65°C (5 to 149°F).

(f) Turn the power switch off.

NG

GO TO STEP 9

OK

3.

CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR)

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NG

CONNECT SECURELY
OK

4.

CHECK CONNECTOR CONNECTION CONDITION (INVERTER WATER PUMP ASSEMBLY CONNECTOR)

Click here 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with P610): P0C7396; Motor Electronics Coolant Pump "A" Component Internal Failure+

NG

CONNECT SECURELY
OK

5.

CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INVERTER WATER PUMP ASSEMBLY)

(a) Disconnect the A57 hybrid vehicle control ECU connector.

(b) Disconnect the A6 inverter water pump assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):

Tester Connection

Condition

Specified Condition

A57-33 (NIWP) - A6-2 (NWP)

Power switch off

Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection

Condition

Specified Condition

A57-33 (NIWP) or A6-2 (NWP) - Body ground and other terminals

Power switch off

10 kΩ or higher

HINT:

Check the condition (looseness, deterioration, etc.) of the wire to body ground for the inverter water pump assembly.

*a

Front view of wire harness connector

(to Hybrid Vehicle Control ECU)

*b

Front view of wire harness connector

(to Inverter Water Pump Assembly)

(d) Reconnect the A6 inverter water pump assembly connector.

(e) Reconnect the A57 hybrid vehicle control ECU connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

6.

CHECK HYBRID VEHICLE CONTROL ECU

(a) Disconnect the A6 inverter water pump assembly connector.

(b) Turn the power switch on (IG).

(c) Measure the voltage according to the value(s) in the table below.

*a

Component with harness connected

(Hybrid Vehicle Control ECU)

-

-

Standard Voltage:

Tester Connection

Condition

Specified Condition

A57-33 (NIWP) - I3-3 (E1)

Power switch on (IG)

11 to 14 V

(d) Turn the power switch off.

(e) Reconnect the A6 inverter water pump assembly connector.

NG

REPLACE HYBRID VEHICLE CONTROL ECU

OK

7.

CLEAR DTC

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NEXT

8.

PERFORM ACTIVE TEST USING TECHSTREAM (ACTIVATE THE INVERTER WATER PUMP)

NOTICE:

Be sure to perform the inspection with the auxiliary battery voltage at 11 V or more.

HINT:

When the auxiliary battery voltage is low, the inverter water pump assembly may not operate.

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Enter the following menus: Powertrain / Hybrid Control / Active Test / Activate the Inverter Water Pump.

(d) Perform the "Activate the Inverter Water Pump" Active Test.

Powertrain > Hybrid Control > Active Test

Tester Display

Activate the Inverter Water Pump

(e) Connect an oscilloscope between the hybrid vehicle control ECU terminals specified in the table below, and measure the waveform.

*a

Component with harness connected

(Hybrid Vehicle Control ECU)

-

-

Item

Content

Terminal

A57-33 (NIWP) - I3-3 (E1)

Equipment Setting

5 V/DIV., 5 ms./DIV.

Condition

Power switch on (IG), during Active Test

OK:

The period of the wavelength is 13 msec or less.

(f) Turn the power switch off.

OK

REPLACE HYBRID VEHICLE CONTROL ECU

NG

GO TO STEP 12

9.

CHECK CONNECTOR CONNECTION CONDITION (INVERTER WATER PUMP ASSEMBLY CONNECTOR)

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NG

GO TO STEP 14

OK

10.

CHECK HARNESS AND CONNECTOR (INVERTER WATER PUMP ASSEMBLY - IGCT RELAY)

(a) Remove the IGCT relay from the No. 1 engine room relay block and No. 1 junction block assembly.

(b) Disconnect the A6 inverter water pump assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

*1

No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

*2

IGCT Relay Holder

*a

Front view of wire harness connector

(to Inverter Water Pump Assembly)

-

-

Standard Resistance:

Tester Connection

Condition

Specified Condition

A6-4 (+BWP) - 5 (IGCT relay holder)

Power switch off

Below 1 Ω

NOTICE:

Do not apply excessive force when using the probes of the tester to perform the inspection. If excessive force is used, the terminals will be damaged.

HINT:

  • Connectors

    Slightly shake the connector vertically and horizontally.

  • Wire Harness

    Slightly shake the wire harness vertically and horizontally.

    The connector joint and fulcrum of the vibration are the major areas that should be checked thoroughly.

  • No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

    Apply slight vibration with a finger to the No. 1 engine room relay block and No. 1 junction block assembly and check whether a malfunction occurs.

  • INV W/PMP fuse

    Apply slight vibration with a finger to the INV W/PMP fuse and check whether a malfunction occurs.

  • IGCT relay

    Apply slight vibration with a finger to the IGCT relay and check whether a malfunction occurs.

*a

Example

*b

Shake Slightly

*c

Vibrate Slightly

(d) Reconnect the A6 inverter water pump assembly connector.

(e) Install the IGCT relay.

NG

GO TO STEP 15

OK

11.

CHECK HARNESS AND CONNECTOR (INVERTER WATER PUMP ASSEMBLY - BODY GROUND)

(a) Disconnect the A6 inverter water pump assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

A6-1 (GND) - Body ground

Power switch off

Below 1 Ω

*a

Front view of wire harness connector

(to Inverter Water Pump Assembly)

(c) Reconnect the A6 inverter water pump assembly connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

12.

REPLACE INVERTER WATER PUMP ASSEMBLY

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NEXT

13.

ADD HV COOLANT AND PERFORM AIR BLEEDING

(a) After replacing the inverter water pump assembly, add HV coolant and perform air bleeding.

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NEXT

END

14.

CHECK FUSE (INV W/PMP)

(a) Remove the INV W/PMP fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

*1

No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

*2

INV W/PMP Fuse

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

INV W/PMP fuse

Always

Below 1 Ω

(c) Install the INV W/PMP fuse.

OK

CONNECT SECURELY (INVERTER WATER PUMP ASSEMBLY CONNECTOR)
NG

GO TO STEP 18

15.

CHECK INSTALLATION CONDITION (INV W/PMP FUSE)

(a) Check installation condition of the INV W/PMP fuse.

OK:

INV W/PMP fuse is installed correctly.

NG

GO TO STEP 19

OK

16.

CHECK HARNESS AND CONNECTOR (INVERTER WATER PUMP ASSEMBLY CIRCUIT)

(a) Remove the INV W/PMP fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

(b) Remove the IGCT relay from the No. 1 engine room relay block and No. 1 junction block assembly.

(c) Disconnect the A6 inverter water pump assembly connector.

(d) Measure the resistance according to the value(s) in the table below.

*1

No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

*2

INV W/PMP Fuse Holder

*3

IGCT Relay Holder

-

-

*a

Front view of wire harness connector

(to Inverter Water Pump Assembly)

-

-

Standard Resistance:

Tester Connection

Condition

Specified Condition

2 (INV W/PMP fuse holder) - A6-4 (+BWP)

Power switch off

Below 1 Ω

1 (INV W/PMP fuse holder) - 5 (IGCT relay)

Power switch off

Below 1 Ω

2 (INV W/PMP fuse holder) or A6-4 (+BWP) - Body ground and other terminals

Power switch off

10 kΩ or higher

NOTICE:

Do not apply excessive force when using the probes of the tester to perform the inspection. If excessive force is used, the terminals will be damaged.

(e) Reconnect the A6 inverter water pump assembly connector.

(f) Install the IGCT relay.

(g) Install the INV W/PMP fuse.

NG

GO TO STEP 21

OK

17.

CHECK FUSE (INV W/PMP)

(a) Remove the INV W/PMP fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

*1

No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

*2

INV W/PMP Fuse

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

INV W/PMP fuse

Always

Below 1 Ω

(c) Install the INV W/PMP fuse.

OK

REPAIR OR REPLACE HARNESS OR CONNECTOR (INV W/PMP FUSE HOLDER TERMINAL)
NG

GO TO STEP 22

18.

CONNECT SECURELY

(a) Connect the inverter water pump assembly connector securely.

NEXT

REPLACE FUSE (INV W/PMP)

19.

CHECK FUSE HOLDER TERMINAL (INV W/PMP FUSE)

(a) Check the terminals of the INV W/PMP fuse holder.

OK:

The terminals of the INV W/PMP fuse holder are not bent, loose or corroded.

NG

GO TO STEP 26

OK

20.

CHECK FUSE (INV W/PMP)

(a) Remove the INV W/PMP fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

*1

No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

*2

INV W/PMP Fuse

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

INV W/PMP fuse

Always

Below 1 Ω

(c) Install the INV W/PMP fuse.

OK

CONNECT SECURELY (INV W/PMP FUSE)
NG

REPLACE FUSE (INV W/PMP)

21.

CHECK FUSE (INV W/PMP)

(a) Remove the INV W/PMP fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

*1

No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

*2

INV W/PMP Fuse

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

INV W/PMP fuse

Always

Below 1 Ω

(c) Install the INV W/PMP fuse.

OK

REPAIR OR REPLACE HARNESS OR CONNECTOR
NG

GO TO STEP 27

22.

CHECK HARNESS AND CONNECTOR (INVERTER WATER PUMP ASSEMBLY - BODY GROUND)

(a) Disconnect the A6 inverter water pump assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

A6-1 (GND) - Body ground

Power switch off

Below 1 Ω

*a

Front view of wire harness connector

(to Inverter Water Pump Assembly)

(c) Reconnect the A6 inverter water pump assembly connector.

NG

GO TO STEP 27

OK

23.

CHECK FUSE HOLDER TERMINAL (INV W/PMP FUSE)

(a) Check the terminals of the INV W/PMP fuse holder.

OK:

The terminals of the INV W/PMP fuse holder are not bent, loose or corroded.

NG

GO TO STEP 28

OK

24.

REPLACE INVERTER WATER PUMP ASSEMBLY

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NEXT

25.

ADD HV COOLANT AND PERFORM AIR BLEEDING

(a) After replacing the inverter water pump assembly, add HV coolant and perform air bleeding.

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NEXT

REPLACE FUSE (INV W/PMP)

26.

CHECK FUSE (INV W/PMP)

(a) Remove the INV W/PMP fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

*1

No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly

*2

INV W/PMP Fuse

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

INV W/PMP fuse

Always

Below 1 Ω

(c) Install the INV W/PMP fuse.

OK

REPAIR OR REPLACE HARNESS OR CONNECTOR (INV W/PMP FUSE HOLDER TERMINAL)
NG

GO TO STEP 28

27.

REPAIR OR REPLACE HARNESS OR CONNECTOR
NEXT

REPLACE FUSE (INV W/PMP)

28.

REPAIR OR REPLACE HARNESS OR CONNECTOR (INV W/PMP FUSE HOLDER TERMINAL)

(a) Repair or replace the terminals of the INV W/PMP fuse holder.

NEXT

REPLACE FUSE (INV W/PMP)