HYBRID CONTROL SYSTEM, Diagnostic DTC:P0A78-505, P0A78-806

DTC Code DTC Name
P0A78-505 Drive Motor "A" Inverter Performance
P0A78-806 Drive Motor "A" Inverter Performance

DTC SUMMARY

MALFUNCTION DESCRIPTION

These DTCs indicate that a large current flowed in the inverter for the motor. The cause of this malfunction may be one of the following:


  1. Internal inverter malfunction:


    • Internal circuit malfunction in the inverter for the motor

    • Malfunction in ECU that controls the inverter

DESCRIPTION

For a description of the inverter Click here.

If the motor inverter overheats, has a circuit malfunction, or has an internal short, the inverter transmits this information to the MG ECU via the motor inverter fail signal line. If an abnormal amount of current flows through the motor inverter, the MG ECU detects it and sends a signal to inform the power management control ECU of the malfunction.

Tech Tips

The term "drive motor A" indicates motor (MG2).

DTC No. INF Code DTC Detection Condition Trouble Area
P0A78 505

Motor inverter fail signal detected (overcurrent due to MG ECU malfunction)*

(1 trip detection logic)

 Inverter with converter assembly
806

Abnormal motor (MG2) current value detected (MG ECU malfunction)*

(1 trip detection logic)

MONITOR DESCRIPTION

P0A78 (INF 505):

If excessive amperage flows through the motor inverter due to an internal short, the motor inverter will transmit an inverter fail signal to the MG ECU. Upon receiving this signal, the power management control ECU will illuminate the MIL and set a DTC.

P0A78 (INF 806):

The MG ECU monitors the motor inverter electric current. If the current exceeds the threshold level for a specified period of time, the power management control ECU will illuminate the MIL and set a DTC.

MONITOR STRATEGY

Related DTCs

P0A78 (INF 505): MFIV detection (Over current malfunction)

P0A78 (INF 806): Motor inverter abnormal current
Required sensors / components Motor inverter
Frequency of operation Continuous
Duration TMC's intellectual property
MIL operation 1 driving cycle
Sequence of operation None

TYPICAL ENABLING CONDITIONS

The monitor will run whenever the following DTCs are not present TMC's intellectual property
Other conditions belong to TMC's intellectual property -

TYPICAL MALFUNCTION THRESHOLDS

TMC's intellectual property -

COMPONENT OPERATING RANGE

Power management control ECU DTC P0A78 (INF 505/806) is not detected

CONFIRMATION DRIVING PATTERN

A01I3BNE01

  1. Connect the Techstream to the DLC3.

  2. Turn the power switch on (IG) and turn the Techstream on.

  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

  4. Turn the power switch off and wait for 30 seconds or more.

  5. Turn the power switch on (IG) and turn the Techstream on.

  6. Turn the power switch on (READY).

  7. With the shift lever in P, wait for 5 seconds. [A]

    Tech Tips

    Check that there are no abnormalities (abnormal sounds, coolant leaks, DTC output, etc).

  8. Perform a road test according to the freeze frame data "Vehicle Spd" for approximately 10 minutes. [B]

  9. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes. [C]

  10. Read the current DTCs.

    Tech Tips


    • If a current DTC is output, the system is malfunctioning.

    • If a current DTC is not output and want to confirm permanent DTC, perform the following procedure.

  11. Check that permanent DTCs are cleared.

  12. If the permanent DTCs are not cleared, perform a universal trip, and then check for permanent DTCs again.

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 removing 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 Click here.

    Tech Tips

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

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 (READY) and wait for 5 seconds or more.

  2. Perform a road test according to the freeze frame data and item "Vehicle Spd" for approximately 10 minutes.

PROCEDURE


  1. CHECK DTC OUTPUT (HYBRID CONTROL)


    1. Connect the Techstream 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
      P0A78-202 is not output. A
      P0A78-202 is also output. B

      Note


      • If P0A78-202 is output, troubleshoot it first. After completing the troubleshooting for P0A78-202, return to perform troubleshooting for this DTC.

      • Parts repaired or replaced during troubleshooting for P0A78-202 do not need to be re-inspected in this diagnosis procedure.

    5. Turn the power switch off.


    B

    GO TO DTC CHART (P0A78-202) Click here

    A

  2. CHECK DTC OUTPUT (HYBRID CONTROL)


    1. Connect the Techstream 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.

      Tech Tips


      • If P0A78-202 was not output in step 1 of this diagnosis procedure, check Table 1 below.

      • If P0A78-202 was output in step 1 of this diagnosis procedure, repair that DTC first, then check Table 2 below.

      Result
      Result Proceed to
      P0A78-505 or 806 only is output, or DTCs except the ones in the tables below are also output. A
      Any of the following DTCs are also output. B
      Table 1
      Malfunction Content Relevant DTC
      Microcomputer malfunction P0A1A (all INF codes)*1 Generator Control Module
      P0A1B-168, 192, 193, 198, 661, 786, 794, 795, 796 Drive Motor "A" Control Module
      P0A1D (all INF codes)*1 Hybrid Powertrain Control Module
      Power source circuit malfunction P0A1B-163, 164, 511, 512 Drive Motor "A" Control Module
      Sensor and actuator circuit malfunction 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
      P0A4B-253 Generator Position Sensor Circuit
      P0A4C-513 Generator Position Sensor Circuit Range / Performance
      P0A4D-255 Generator Position Sensor Circuit Low
      P0A60 (all INF codes)*1 Drive Motor "A" Phase V Current
      P0A63 (all INF codes)*1 Drive Motor "A" Phase W Current
      P0A72 (all INF codes)*1 Generator Phase V Current
      P0A75 (all INF codes)*1 Generator Phase W Current
      System malfunction P0A78-266, 267, 586 Drive Motor "A" Inverter Performance
      P0A94-585, 587, 589, 590 DC / DC Converter Performance
      P0C76-523 Hybrid Battery System Discharge Time Too Long
      Table 2
      Malfunction Content Relevant DTC
      Microcomputer malfunction P0A1A (all INF codes)*1 Generator Control Module
      P0A1B-168, 192, 193, 198, 661, 786, 794, 795, 796 Drive Motor "A" Control Module
      P0A1D (all INF codes)*1 Hybrid Powertrain Control Module
      Power source circuit malfunction P0A1B-163, 164, 511, 512 Drive Motor "A" Control Module
      Sensor and actuator circuit malfunction 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
      P0A4B-253 Generator Position Sensor Circuit
      P0A4C-513 Generator Position Sensor Circuit Range / Performance
      P0A4D-255 Generator Position Sensor Circuit Low
      P0A60-294 Drive Motor "A" Phase V Current
      P0A63-302 Drive Motor "A" Phase W Current
      P0A72 (all INF codes)*1 Generator Phase V Current
      P0A75 (all INF codes)*1 Generator Phase W Current
      System malfunction P0A78-266, 267, 586 Drive Motor "A" Inverter Performance
      P0A94-585, 587, 589, 590 DC / DC Converter Performance
      P0C76-523 Hybrid Battery System Discharge Time Too Long

      Tech Tips


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

      • P0A78-505 or P0A78-806 may be output as a result of the malfunction indicated by the DTCs above.


        1. The chart above is listed in inspection order of priority.

        2. Check DTCs that are output at the same time by following the listed order. (The main cause of the malfunction can be determined without performing unnecessary inspections.)

    5. Turn the power switch off.


    B

    GO TO DTC CHART (HYBRID CONTROL SYSTEM) Click here

    A

    REPLACE INVERTER WITH CONVERTER ASSEMBLY Click here