P0A94-442

DESCRIPTION

The boost converter boosts a direct-current voltage rating of 288 V to a direct-current voltage of approximately 650 V. The inverter converts the voltage that has been boosted by the boost converter into alternating current, which is used for driving the Motor, Generator, and Rear Motor. When the Generator, Motor, and Rear Motor operate as a Generator, the alternating-current voltage from the Motor, Generator, and Rear Motor is converted into direct-current voltage by the inverter. Then the boost converter drops this voltage to a direct-current voltage rating of 288 V in order to charge the HV battery.

The MG ECU uses a voltage sensor that is built into the boost converter to detect the high voltage (VL) before it is boosted. It also uses a voltage sensor that is built into the inverter to detect the high voltage (VH) after it is boosted. Based on the voltage before and after it is boosted, the MG ECU controls the operation of the boost converter to boost the voltage to the target voltage.

DTC No.	INF Code	DTC Detection Condition	Trouble Area
P0A94	442	Abnormal voltage execution value	w/ converter inverter assembly (MG ECU)

MONITOR DESCRIPTION

If the difference between the requested boost converter voltage and the actual boost converter voltage exceeds a predetermined value, the HV control ECU determines that there is malfunction in the execution or monitoring of the boost converter voltage. Then, 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.

2. Turn the ignition switch to the ON position.

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

4. Read output DTCs. (Click here)
   

   Result:

   The DTCs shown in the table below are output:

   DTC No.	Relevant Diagnosis
   P0A1A (all details), P0A1B (all details), P0A1C (all details)	MG ECU circuit malfunction
   P0A1D (all details)	HV ECU circuit malfunction
   P0A3F-243, P0A40-500, P0A41-245	Motor resolver circuit
   P0A45-669, P0A46-671, P0A47-670	Rear motor resolver malfunction
   P0A4B-253, P0A4C-513, P0A4D-255	Generator resolver circuit
   P0A51-174, P0A55-687	MG ECU circuit malfunction
   P0A60 (all details), P0A63 (all details)	Motor current sensor circuit
   P0A69 (all details), P0A6C (all details)	Rear motor current sensor circuit
   P0A72 (all details), P0A75 (all details)	Generator current sensor circuit
   P0A78 (all details)	Motor inverter function malfunction
   P0A79 (all details)	Rear motor inverter function malfunction
   P0A7A (all details)	Generator inverter function malfunction
   P0A7F (all details), P0A80	HV battery system malfunction
   P0A82, P0A84, P0A85	HV battery cooling fan circuit malfunction
   P0A90 (all details)	Motor function malfunction
   P0A91 (all details)	Rear motor function malfunction
   P0A92 (all details)	Generator function malfunction
   P0A94 (Except for 442)	Boost converter circuit
   P0A95	HV battery high voltage fuse blown out
   P0AA1 (all details), P0AA2 (all details), P0AA4 (all details), and P9AA5-229	System main relay circuit
   P0AA6 (all details), P3004 (all details)	High-voltage system
   P3000 (all details)	HV battery system 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. P0A94-442 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.

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.

2. 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.
      

3. 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