DTC    P0A78-283    Drive Motor "A" Inverter Performance

DTC    P0A78-285    Drive Motor "A" Inverter Performance

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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.
The MG ECU monitors the motor inverter fail signal line and detects a malfunction.

DTC No.
INF Code
DTC Detection Condition
Trouble Area
P0A78
283
Short to +B in the motor inverter fail (MFIV) signal line
  1. w/ converter inverter assembly (MG ECU)
↑
285
Open or short to GND in the motor inverter fail (MFIV) signal line
  1. w/ converter inverter assembly (MG ECU)

MONITOR DESCRIPTION

The MG ECU monitors the motor inverter fail (MFIV) signal line. If the MG ECU detects an open or short malfunction of the MFIV signal circuit, 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.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.



NG
CONNECT SECURELY
OK

REPLACE W/ CONVERTER INVERTER ASSEMBLY