RX400h · Service Manual HYBRID SYSTEM

P0A7A-322

Diagnostic trouble codes

DESCRIPTION

Refer to the description of the inverter. (Click here)
If the generator inverter circuit is opened or shorted, or if the circuit overheats, the information is transmitted from the inverter to the GFIV terminal of the MG ECU via the generator inverter fail signal line.
DTC No.
 INF Code
 DTC Detection Condition
 Trouble Area
P0A7A
 322
 Generator inverter fail signal detection (overheating)
  1. Wire harness or connector
  2. Inverter cooling system
  3. Water pump w/ motor & bracket assembly
  4. Cooling fan circuit
  5. Hybrid vehicle transaxle assembly
  6. w/ converter inverter assembly (MG ECU)
  7. Engine

MONITOR DESCRIPTION

If the generator inverter overheats, it transmits an 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 DTC. (Click here)

    Result:
    The DTCs shown in the table below are output:
    DTC No.
    		 Relevant Diagnosis
    P0A1D
    		 HV ECU circuit malfunction
    P0A2B, P0A2C, P0A2D
    		 Motor temperature sensor circuit
    P0A37, P0A38, P0A39
    		 Generator temperature sensor circuit
    P0A3F, P0A40, P0A41
    		 Motor resolver circuit
    P0A4B, P0A4C, P0A4D
    		 Generator resolver circuit
    P0A60, P0A63
    		 Motor current sensor circuit
    P0A72, P0A75
    		 Generator current sensor circuit
    P0A78
    		 Motor inverter function malfunction
    P0A7A (Except for 322, 809, 810, and 811)
    		 Generator inverter function malfunction
    P0A90
    		 Motor function malfunction
    P0A92
    		 Generator function malfunction
    P0A94
    		 Boost converter circuit
    P0AA1, P0AA2, P0AA4, P0AA5
    		 System main relay circuit
    P0AA6, P3004
    		 High-voltage system
    P0A79
    		 Rear motor inverter function malfunction
    P0A45, P0A46, P0A47
    		 Rear motor resolver malfunction
    P0A69, P0A6C, P0A55
    		 Rear motor current sensor circuit
    P0A1A, P0A1B, P0A1C
    		 MG ECU circuit malfunction

    NOTICE:
    If P0A7A-322 is output, repair the malfunctioning area indicated by the DTC, or replace the w/ converter inverter assembly after repairing the malfunctioning area.

    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. P0A7A-322 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 QUANTITY OF HV COOLANT

  1. Check the inverter coolant level.

    OK:
    There is sufficient amount of coolant for the inverter.



 NG
CHECK FOR COOLANT LEAKS AND ADD COOLANT
OK


3. CHECK COOLANT HOSE

  1. A105138E02
    Check if the hoses of the cooling system are not bent or clogged.

    OK:
    The hoses of the cooling system are not bent or clogged.



 NG
CORRECT TO NORMAL CONDITION
OK


4. CHECK CONNECTION CONDITION OF WATER PUMP CONNECTOR (LOOSENESS AND POOR CONTACT)

  1. A105139E01
    Check the connection of the water pump w/ motor & bracket assembly connector.

    OK:
    Connector is connected securely and there is no poor connection.



 NG
CONNECT SECURELY
OK


5. PERFORM ACTIVE TEST BY INTELLIGENT TESTER (WATER PUMP)

  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 / Active Test / Active Water Pump.

  1. During the water pump active test, check operation of the water pump w/ motor & bracket assembly.

    OK:
    There are ripples in the reservoir tank coolant.

    HINT:
    The water pump is also activated in the READY-on state.



 NG
CHECK WATER PUMP W/ MOTOR & BRACKET ASSEMBLY CIRCUIT
OK


6. PERFORM ACTIVE TEST BY INTELLIGENT TESTER (COOLING FAN)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to the ON position.

  1. Select the following menu items: Powertrain / Engine / Active Test / Cooling Fan.

  1. Perform the cooling fan active test.

OK:
The electric cooling fan rotates.



 NG
CHECK COOLING FAN CIRCUIT
OK


7. CHECK CONNECTION CONDITION OF HYBRID VEHICLE CONTROL ECU CONNECTOR

  1. A103658E18
    Check the connections of all HV control ECU connectors.

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



 NG
CONNECT SECURELY
OK


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

CAUTION:
Be sure to wear insulated gloves.

  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. Be sure to 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. A103665E03
    Check the connections of the MG ECU connectors.

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



 NG
CONNECT SECURELY
OK


9. INSPECT HYBRID VEHICLE TRANSAXLE ASSEMBLY (GENERATOR)

CAUTION:
Be sure to wear insulated gloves.

  1. A108061E05
    Check that the service plug grip is removed.

  1. Disconnect the three-phase AC cables for Motor and Generator from the w/ converter inverter assembly.

  1. A111753E02
    Using a milliohmmeter, measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    U - V
    		 36 to 43 mΩ (20°C)
    V - W
    		 36 to 43 mΩ (20°C)
    W - U
    		 36 to 43 mΩ (20°C)

    NOTICE:
    If the Generator temperature is too high, the resistance changes greatly. Therefore, measure the resistance at least 8 hours after the vehicle is stopped.

  1. To correct the resistance varying depending on the temperature, use the following formula to calculate the resistance at 20°C.

    HINT:
    1. R20 = Rt / {1 + 0.00393 X (T - 20)}
    2. R20: Resistance at 20 °C (mΩ)
    3. Rt: Measured resistance (mΩ)
    4. T: Temperature when the resistance is measured (°C)

  1. Calculate the difference between the maximum and minimum resistance.

    Standard resistance:
    Difference is 3 mΩ or less

  1. Using a megohmmeter, measure the insulation resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    U - Body ground and shielded wire ground
    		 10 MΩ or higher
    V - Body ground and shielded wire ground
    		 10 MΩ or higher
    W - Body ground and shielded wire ground
    		 10 MΩ or higher



NG
REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY
OK


10. CHECK ENGINE START

  1. Put the vehicle into the READY-on state. Check if the engine starts.

    OK:
    The engine starts.



 OK
REPLACE W/ CONVERTER INVERTER ASSEMBLY
NG


11. CHECK CRANKSHAFT PULLEY REVOLUTION (P POSITION)

  1. Turn the ignition switch off, move the shift lever to the P position, and lift up the vehicle.

    CAUTION:
    Do not put the vehicle into the READY-on state while performing this inspection. Be sure to turn the ignition switch off because the engine may start.

  1. Turn the crank pulley by hand to check if the crankshaft rotates.

    OK:
    The crankshaft rotates.



 NG
REPLACE W/ CONVERTER INVERTER ASSEMBLY
OK


12. CHECK CRANKSHAFT PULLEY REVOLUTION (N POSITION)

  1. Turn the ignition switch off, move the shift lever to the N position, and lift up the vehicle.

    CAUTION:
    Do not put the vehicle into the READY-on state while performing this inspection. Be sure to turn the ignition switch off because the engine may start.

  1. Turn the crank pulley by hand to check if the crankshaft rotates.

    OK:
    The crankshaft rotates.



 OK
REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY
NG

REPAIR OR REPLACE ENGINE


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