DTC    P0A78-286    Drive Motor "A" Inverter Performance

for Preparation Click here


DESCRIPTION

Refer to the description of the inverter. (Click here)
If the motor inverter has a circuit malfunction, overheat, or internal short, the inverter transmits this information to the MFIV terminal of the MG ECU via the motor inverter fail signal line.

DTC No.
INF Code
DTC Detection Condition
Trouble Area
P0A78
286
Motor inverter fail signal detection (circuit malfunction)
  1. w/ converter inverter assembly (MG ECU)

MONITOR DESCRIPTION

If the motor inverter detects a circuit malfunction, it transmits a motor inverter fail signal to the MG ECU. Upon receiving this signal, the HV control ECU illuminates the MIL and sets a DTC.

INSPECTION PROCEDURE

CAUTION:
  1. Before inspecting the high-voltage system, take safety precautions to prevent electrical shocks, such as wearing insulated gloves and removing the service plug grip. After removing the service plug grip, put it in your pocket to prevent other technicians from reconnecting it while you are working on the high-voltage system.
  2. After disconnecting the service plug grip, wait for at least 5 minutes before touching any of the high-voltage connectors or terminals.

HINT:
At least 5 minutes is required to discharge the high-voltage capacitor inside the w/ converter inverter assembly.

1.READ OUTPUT DTC (HV)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to the ON position.

  1. Select the following menu items: Powertrain / Hybrid Control / DTC.

  1. Read output DTCs. (Click here)

    Result:
    The DTCs shown in the table below are output:

    DTC No.
    		INF Code
    		Detection Item
    P0A78
    		283, 285
    		Motor inverter function malfunction
    P0A3F
    		243
    		Motor resolver circuit
    P0A40
    		500
    		Motor resolver output is out of normal range
    P0A41
    		245
    		Motor resolver circuit (Low)
    P0A45
    		669
    		Interphase short in rear motor resolver circuit
    P0A46
    		671
    		Rear motor resolver output is out of normal range
    P0A47
    		670
    		Rear motor resolver circuit (Low)
    P0A4B
    		253
    		Generator resolver circuit
    P0A4C
    		513
    		Generator resolver output is out of normal range
    P0A4D
    		255
    		Generator resolver circuit (Low)
    P0A93
    		346
    		Inverter cooling system
    P0A93
    		347
    		Inverter cooling system
    P0A95
    		776
    		Inverter water pump malfunction

    NOTICE:
    If a DTC indicating a malfunction in the above systems is output, repair the malfunctioning area indicated by the DTC and check for DTC outputs. If P0A7A-324 is output, replace the w/ converter inverter assembly.

    HINT:
    1. Turning the ignition switch to the ON position with the service plug grip and inverter cover removed causes interlock switch system DTC P0A0D-350 to be output.
    2. P0A78-286 may be output due to a malfunction which causes the DTCs in the table above to be output. In this case, first troubleshoot the output DTCs in the table above. Then, perform a reproduction test to check that no DTCs are output.



YES
GO TO DTC CHART
NO


2.CHECK CONNECTION CONDITION OF MG ECU CONNECTOR (LOOSENESS AND POOR CONTACT)

CAUTION:
Be sure to wear insulated gloves.



    A103665E01

  1. Turn the ignition switch off and remove the service plug grip. (Click here)

    NOTICE:
    Do not put the vehicle into the READY-on state with the service plug grip removed as this may cause a malfunction.

  1. Remove the inverter cover. (Click here)

    NOTICE:
    1. Wrap the interlock round terminal for the inverter cover with vinyl tape to prevent it from shorting to ground.
    2. Prevent water in the reservoir tank from entering the inverter.
    3. Removing the inverter cover causes the MG ECU board to be exposed. Therefore, temporarily install the inverter cover for each area to be inspected.

  1. Check the connections of the MG ECU connectors.

    OK:
    Connectors are connected securely and there is no poor connection.



OK
CONNECT SECURELY
NG

REPLACE W/ CONVERTER INVERTER ASSEMBLY