DTC    P0A78-279    Drive Motor "A" Inverter Performance

DTC    P0A78-503    Drive Motor "A" Inverter Performance

for Preparation Click here


DESCRIPTION

Refer to the the description of the inverter. (Click here)

DTC No.
INF Code
DTC Detection Condition
Trouble Area
P0A78
279
Motor inverter overvoltage signal detection (overvoltage by w/ converter inverter assembly)
  1. HV relay assembly
  2. w/ converter inverter assembly (MG ECU)
↑
503
Motor inverter overvoltage signal detection (overvoltage by MG ECU malfunction)
  1. HV relay assembly
  2. w/ converter inverter assembly (MG ECU)

MONITOR DESCRIPTION

If the motor inverter detects over-voltage, it transmits an over-voltage 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 DTC. (Click here)

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

    DTC No.
    		INF Code
    		Detection Item
    P0A78
    		266, 280
    		Motor inverter function malfunction
    P0A94
    		558, 559, 588, 589
    		Boost converter circuit malfunction
    P0A95
    		123
    		High voltage fuse blown out
    P0AA1
    		226
    		SMR+ stuck closed
    P0AA2
    		227
    		SMR+ stuck open
    P0AA4
    		228
    		SMR- stuck closed
    P0AA5
    		229
    		SMR- stuck open
    P3004
    		803
    		High-current wiring malfunction

    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. P0A78-284 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 DTC P0A0D-350 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 all MG ECU connectors.

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



NG
CONNECT SECURELY
OK


3.INSPECT HV RELAY ASSEMBLY (SMR2)

CAUTION:
Be sure to wear insulated gloves and protective goggles.

  1. Check that the service plug grip is removed.

  1. Remove the HV relay assembly from the vehicle.



    A108055E07

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

Standard Resistance :
Tester Condition
Specified Condition
S47-1 - S44-1
Below 1 Ω
(Apply auxiliary battery voltage between terminals (CON2 (S48-1) and GND (S48-4))

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

    Standard Resistance :
    Tester Condition
    		Specified Condition
    CON2 (S44-1) - GND (S44-4)
    		20 to 60 Ω
    at -35 to 80°C ( -31 to 176°F)



NG
REPLACE HV RELAY ASSEMBLY
OK


4.INSPECT HV RELAY ASSEMBLY (SMR3)

CAUTION:
Be sure to wear insulated gloves.

  1. Check that the service plug grip is removed.



    A108054E04

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

Standard Resistance :
Tester Condition
Specified Condition
S49-1 - S45-1
Below 1 Ω
(Apply auxiliary battery voltage between terminals (CON3 (S48-2) and GND (S48-4))

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

Standard Resistance :
Tester Condition
Specified Condition
CON3 (S44-1) - GND (S44-4)
20 to 60 Ω
at -35 to 80°C ( -31 to 176°F)



NG
REPLACE HV RELAY ASSEMBLY
OK

REPLACE W/ CONVERTER INVERTER ASSEMBLY