Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001N3Z1
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): P0A1B94; Drive Motor "A" Control Module Unexpected Operation; 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]

DTC

P0A1B94

Drive Motor "A" Control Module Unexpected Operation

DTC SUMMARY

MALFUNCTION DESCRIPTION

The hybrid vehicle control ECU monitors the motor generator control ECU (MG ECU).

The cause of this malfunction may be the following:

Motor generator control ECU internal malfunction

  • Motor generator control ECU (MG ECU) malfunction

DESCRIPTION

The hybrid vehicle control ECU monitors the motor generator control ECU (MG ECU) and stores this DTC when it detects a malfunction.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

P0A1B94

Drive Motor "A" Control Module Unexpected Operation

The motor generator control ECU (MG ECU) value received by the hybrid vehicle control ECU exceeds the threshold for a certain period of time.

(1 trip detection logic)
  • Inverter with converter assembly
  • Fusible link block assembly (BATT-MAIN)
  • IGCT-IG fuse
  • IGCT relay

Comes on

Master Warning: Comes on

MONITOR DESCRIPTION

The hybrid vehicle control ECU monitors the motor generator control ECU (MG ECU). If the internal operation is malfunctioning, the hybrid vehicle control ECU illuminates the MIL and stores a DTC.

MONITOR STRATEGY

Related DTCs

P0A1B (INF P0A1B94): Drive motor "A" control module

Required sensors/components

Inverter with converter assembly (MG ECU)

Frequency of operation

Continuous

Duration

TMC's intellectual property

MIL operation

1 driving cycle

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 P0A1B (INF P0A1B94) 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. With power switch on (IG) and wait for 2 minutes or more. [*1]

    HINT:

    • If the vehicle has returned to normal, it can be driven after turning the power switch on (READY).
    • [*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

CAUTION / NOTICE / HINT

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 2021 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [04/2020 - 09/2022]; INTRODUCTION: REPAIR INSTRUCTION: INITIALIZATION

PROCEDURE

1.

CHECK AUXILIARY BATTERY TERMINAL (CONTACT PROBLEM)

(a) Check the connection of the negative (-) and positive (+) auxiliary battery terminals.

OK:

The terminals are connected securely and there is no contact problem.

HINT:

If performing a reproduction test, turn the power switch on (IG) and shake the wire harnesses vertically and horizontally before checking for DTCs.

NG

GO TO STEP 7

OK

2.

CHECK GROUND WIRE CONNECTION CONDITION

(a) Check the installation condition of the ground wires DA and DC.

OK:

The ground wires DA and DC are securely installed.

HINT:

If performing a reproduction test, turn the power switch on (IG) and shake the wire harnesses vertically and horizontally before checking for DTCs.

NG

GO TO STEP 8

OK

3.

CHECK FUSIBLE LINK (BATT-MAIN)

(a) Disconnect the cable from the negative (-) auxiliary battery terminal.

(b) Disconnect the cable from the positive (+) auxiliary battery terminal.

(c) Check the fusible link block assembly (BATT-MAIN) for improper installation.

OK:

The fusible link block assembly is installed securely and there is no contact problem.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A75-1 - A-1 (Positive (+) auxiliary battery terminal)

Power switch off

Below 1 Ω

*1

Fusible Link Block Assembly

(e) Reconnect the cable from the positive (+) auxiliary battery terminal.

(f) Reconnect the cable from the negative (-) auxiliary battery terminal.

NG

GO TO STEP 9

OK

4.

CHECK FUSE (IGCT-IG)

(a) Check the IGCT-IG fuse for improper installation.

OK:

The fuse is installed securely.

HINT:

If performing a reproduction test, turn the power switch on (IG) and gently vibrate the IGCT-IG fuse with a finger before checking for DTCs.

(b) Remove the IGCT-IG 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

IGCT-IG Fuse

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

IGCT-IG fuse

Power switch off

Below 1 Ω

(d) Install the IGCT-IG fuse.

NG

GO TO STEP 10

OK

5.

CHECK RELAY (IGCT)

(a) Check the IGCT relay for improper installation.

OK:

The relay is installed securely.

HINT:

If performing a reproduction test, turn the power switch on (IG) and gently vibrate the IGCT relay with a finger before checking for DTCs.

(b) Remove the IGCT relay 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

IGCT Relay

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

3 - 5

Auxiliary battery voltage not applied between terminals 1 and 2

10 kΩ or higher

Auxiliary battery voltage applied between terminals 1 and 2

Below 1 Ω

*1

IGCT Relay

(d) Install the IGCT relay.

NG

GO TO STEP 11

OK

6.

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

HINT:

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

Result

Proceed to

P0A1B94 only is output

A

DTCs except P0A1B94 are output

B

(e) Turn the power switch off.

A

REFER TO REPLACE INVERTER WITH CONVERTER ASSEMBLY PARTS

B

GO TO DTC CHART (HYBRID CONTROL SYSTEM)

7.

CONNECT SECURELY
NEXT

GO TO STEP 12

8.

CONNECT SECURELY
NEXT

GO TO STEP 12

9.

REPAIR OR REPLACE MALFUNCTIONING PARTS
NEXT

GO TO STEP 12

10.

REPAIR OR REPLACE MALFUNCTIONING PARTS
NEXT

GO TO STEP 12

11.

REPAIR OR REPLACE MALFUNCTIONING PARTS
NEXT

12.

CLEAR DTC

Click here 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY with P610): P06881F; ECM/PCM Power Relay Sense Circuit Intermittent+

NEXT

13.

SIMULATION TEST

(a) Turn the power switch on (IG) and wait for 2 minutes or more.

(b) Turn the power switch off.

NEXT

14.

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

No DTCs are output

A

P0A1B94 only is output

B

DTCs except P0A1B94 are output

C

(e) Turn the power switch off.

A

END
B

REFER TO REPLACE INVERTER WITH CONVERTER ASSEMBLY PARTS

C

GO TO DTC CHART (HYBRID CONTROL SYSTEM)