HYBRID CONTROL SYSTEM, Diagnostic DTC:P0A51-174

DTC Code DTC Name
P0A51-174 Drive Motor "A" Current Sensor Circuit

DESCRIPTION

The MG ECU, which is built into the inverter with converter assembly, monitors its internal operation and will store DTCs when the system is malfunctioning.

DTC No. Detection Item DTC Detection Condition Trouble Area Warning Indicate
P0A51-174 Drive Motor "A" Current Sensor Circuit

Drive motor current sensor high resolution circuit signal is out of range or there is a difference between it and the drive motor current sensor low resolution circuit current value.

(1 trip detection logic)

  • Inverter with converter assembly

  • Wire harness or connector

Master Warning Light:

Comes on

CAUTION / NOTICE / HINT

CAUTION:


  • B006JFB
    B006JM4

    Before the following operations are conducted, take precautions to prevent electric shock by turning the power switch off, wearing insulated gloves, and removing the service plug grips from both FC stack assembly and EV battery.


    • Inspecting the high-voltage system

    • Disconnecting the low voltage connector of the inverter with converter assembly

    • Disconnecting the low voltage connector of the EV battery

    • Disconnecting the low voltage connector of the FC stack assembly

    • Disconnecting the low voltage connector of the FC converter assembly

      Tech Tips

      No removal order is specified for the service plug grips of the FC stack assembly and EV battery.

  • B006JBZ

    After removing the service plug grip from the EV battery, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system. After removing the service grip from the FC stack assembly, store it in a safe location and use the "HIGH-VOLTAGE, DO NOT TOUCH" sign to notify other technicians that you are working on the high-voltage system.

  • B000ZMTC04
    *a Without waiting for 10 minutes

    After removal of the service plug grips of both FC stack assembly and EV battery, wait for at least 10 minutes before touching the high-voltage connectors and terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.

    Click here

    Tech Tips

    At least 10 minutes are necessary to discharge the high-voltage capacitors inside the inverter with converter assembly and FC stack assembly.

Note


  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

    Click here

  • When reinstalling the service plug grip to the FC stack assembly or the EV battery, slide the lever of the service plug until the letters "UNLOCK" are completely hidden, and insert it firmly.

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  • When the vehicle is parked with the power switch off, if the FC control ECU judges that the FC stack temperature will go below 0°C (32°F), it activates the FC air compressor, hydrogen pump and FC cooling water pump for a maximum of 180 seconds and drains water from the FC stack assembly. When performing inspection or repairs with the power switch off (not on (IG) or on (READY)), disconnect the cable from the negative (-) auxiliary battery terminal before performing work (If the auxiliary battery voltage is needed to conduct inspection, warm up the FC system beforehand).

Tech Tips

After the repair, clear the DTCs and perform the following procedure to check that DTCs are not output.


  1. Turn the power switch on (IG) and wait for 5 seconds or more.

PROCEDURE


  1. CHECK DTC OUTPUT (EV)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / EV / Trouble Codes.

    4. Check for DTCs.


      Powertrain > EV > Trouble Codes
      Result
      Result Proceed to
      P0A51-174 only is output, or DTCs except the ones in the table below are also output. A
      Any of the following DTCs are also output. B
      Relevant DTC
      P0A60 (all INF codes)*1 Drive Motor "A" Phase V Current
      P0A63 (all INF codes)*1 Drive Motor "A" Phase W Current
      P0A78-113, 287, 505, 506 Drive Motor "A" Inverter Performance

      Tech Tips


      • *1: If any INF codes are output for this DTC, refer to the corresponding diagnostic procedure.

      • P0A51-174 may be stored due to a malfunction which causes the DTCs in the preceding table to be stored. In this case, first troubleshoot the output DTCs in the preceding table. Then, perform a reproduction test to check that no DTCs are output.

    5. Turn the power switch off.


    B

    GO TO DTC CHART (HYBRID CONTROL SYSTEM) Click here

    A

  2. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR)

    Result
    Result Proceed to
    OK A
    NG (The connector is not connected securely.) B
    NG (The terminals are not making secure contact or are deformed, or water or foreign matter exists in the connector.) C

    CAUTION:

    Be sure to wear insulated gloves.


    1. Check that the service plug grip is not installed to FC stack assembly and EV battery.

      Note

      After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

    2. A01MFWK

      Check the connection condition of the low voltage connector of the inverter with converter assembly and the contact pressure of each terminal. Check the terminals for deformation, and check the connector for water ingress and foreign matter.

      Click here

      Note

      Before disconnecting the connector, confirm that it is properly connected by checking that the locking claws are engaged and that the connector does not pull out.

      OK
      - The connector is connected securely.
      - The terminals are not deformed and are connected securely.
      - No water or foreign matter in the connector.
      Result
      Result Proceed to
      OK A
      NG (The connector is not connected securely.) B
      NG (The terminals are not making secure contact or are deformed, or water or foreign matter exists in the connector.) C

    A

    REPLACE INVERTER WITH CONVERTER ASSEMBLY Click here

    B

    CONNECT SECURELY

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR