HYBRID CONTROL SYSTEM, Diagnostic DTC:P0A78-503

DTC Code DTC Name
P0A78-503 Drive Motor "A" Inverter Performance

DESCRIPTION

Refer to the wiring diagram for DTC P0A78-118 Click here.

DTC No. INF Code DTC Detection Condition Trouble Area
P0A78 503 Motor inverter overvoltage signal detection (overvoltage due to MG ECU malfunction) Inverter with converter assembly

INSPECTION PROCEDURE

CAUTION:


  • Before inspecting the high-voltage system or disconnecting the low voltage connector of the inverter with converter assembly, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.

  • After disconnecting the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or 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.

Tech Tips

Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

PROCEDURE


  1. CHECK DTC OUTPUT (HV)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

    4. Check if DTCs are output.

      Result
      Result Proceed to
      P0A78-503 only is output. A
      Any of the following DTCs are also output. B
      DTC No. Relevant Diagnosis
      P0A1A (all INF codes)*1 Generator Control Module
      P0A1B (all INF codes)*1 Drive Motor "A" Control Module
      P0A1C (all INF codes)*1 Drive Motor "B" Control Module
      P0A1D (all INF codes)*1 Hybrid Powertrain Control Module
      P0A60 (all INF codes)*1 Drive Motor "A" Phase V Current
      P0A63 (all INF codes)*1 Drive Motor "A" Phase W Current
      P0A69 (all INF codes)*1 Drive Motor "B" Phase V Current
      P0A6C (all INF codes)*1 Drive Motor "B" Phase W Current
      P0A72 (all INF codes)*1 Generator Phase V Current
      P0A75 (all INF codes)*1 Generator Phase W Current
      P0A3F-243 Drive Motor "A" Position Sensor Circuit
      P0A40-500 Drive Motor "A" Position Sensor Circuit Range/Performance
      P0A41-245 Drive Motor "A" Position Sensor Circuit Low
      P0A45-669 Drive Motor "B" Position Sensor Circuit
      P0A46-671 Drive Motor "B" Position Sensor Circuit Range/Performance
      P0A47-670 Drive Motor "B" Position Sensor Circuit Low
      P0A4B-253 Generator Position Sensor Circuit
      P0A4C-513 Generator Position Sensor Circuit Range/Performance
      P0A4D-255 Generator Position Sensor Circuit Low
      P0A78-266, 267, 287, 505, 506, 586, 806, 807, 808 Drive Motor "A" Inverter Performance
      P0A79-693, 694, 695, 812, 813, 814 Drive Motor "B" Inverter Performance
      P0A7A-325, 517, 518, 809, 810, 811 Generator Inverter Performance
      P0A93-346 Inverter Cooling System Performance
      P0A94-169, 170, 171, 554, 555, 556, 585, 587, 589, 590 DC/DC Converter Performance
      P0ADB-227 Hybrid Battery Positive Contactor Control Circuit Low
      P0ADC-226 Hybrid Battery Positive Contactor Control Circuit High
      P0ADF-229 Hybrid Battery Negative Contactor Control Circuit Low
      P0AE0-228 Hybrid Battery Negative Contactor Control Circuit High
      P0C73-776 Motor Electronics Coolant Pump "A" Control Performance
      P0C76-523 Hybrid Battery System Discharge Time Too Long
      P3004-803 High Voltage Power Resource
      P314A-828 Inverter Coolant Pump Speed Signal

      Tech Tips


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

      • P0A78-503 may be set due to a malfunction which also causes DTCs in the preceding table to be set. In this case, first troubleshoot the output DTCs in the preceding table. Then, perform a test to attempt to reproduce the problems, and check that no DTCs are output.

    5. Turn the power switch off.


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

    CAUTION:

    Be sure to wear insulated gloves.


    1. Check that the service plug grip is not installed.

      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.

      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.

      A01NHWR
    2. Check the connection of the low voltage connector of the inverter with converter assembly.

      OK
      The connector is connected securely and there are no contact problems.

      Tech Tips

      When connecting the connector, insert it with the locking lever in the raised position. Rotate the lever downward and make sure that the connector is pulled into its socket. When the locking lever is in its fully closed position, a click will be heard as its locking claws engage. After the click is heard, pull up on the connector to confirm that it is properly connected.


    NG
    OK