LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2008 >> RX 400h FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 160 (Hybrid Vehicle Control (P310) - RX400H - DTC P0A37-258 Through P0A79-812) >> DTC P0A78-506 Drive Motor "A" Inverter Performance >> Inspection Procedure

Inspection Procedure

WARNING: This page is about a different car, the 2006 Lexus RX 400h. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
  • 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.
  • 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: DIAGNOSIS / OBD/ MOBD / HV ECU / DTC INFO / CURRENT CODES.
    4. Read output DTCs. (See DTC CHECK / CLEAR )

      Result: 

      The DTCs shown in the table below are output 

      OUTPUT DTC (HV)

      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 (Except for 506, 806, 807, and 808) Motor inverter function malfunction
      P0A7A Generator inverter function malfunction
      P0A90 Motor function malfunction
      P0A92 Generator function malfunction
      P0A94 (Except for 554 and 555) Boost converter circuit
      P0AA1, P0AA2, P0AA4, P0AA5 System main relay circuit
      P0AA6, P3004 High-voltage system
      P3226 Boost converter temperature sensor circuit
      P0A79 Rear motor inverter function malfunction
      P3216 Rear motor temperature sensor malfunction
      P0A45, P0A46, P0A47 Rear motor resolver malfunction
      P0A69, P0A6C, P0A55 Rear motor current sensor circuit
      P0A1A, P0A1B, P0A1C MG ECU malfunction

      HINT:

      • 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.
      • P0A78-506 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  DIAGNOSTIC TROUBLE CODE CHART 

    NO: GO TO NEXT STEP 

  2. CHECK CONNECTION CONDITION OF HYBRID VEHICLE CONTROL ECU CONNECTOR (LOOSENESS AND POOR CONTACT) 
    1. Check the connections of the HV control ECU connectors.

      OK: 

      Connectors are connected securely and there is no poor connection. 

    Fig 1: Checking Connection Condition Of Hybrid Vehicle Control ECU Connector (Looseness And Poor Contact)
    G04112043Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: CONNECT SECURELY 

    OK: GO TO NEXT STEP 

  3. 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. (See PRECAUTION )
      NOTE: 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. (See INVERTER WITH CONVERTER )
      NOTE:
      • Wrap the interlock round terminal for the inverter cover with vinyl tape to prevent it from shorting to ground.
      • Prevent water in the reservoir tank from entering the inverter.
      • 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. 

    Fig 2: Checking Connection Condition Of MG ECU Connector (Looseness And Poor Contact)
    G04112044Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: CONNECT SECURELY 

    OK: GO TO NEXT STEP 

  4. CHECK W/ CONVERTER INVERTER ASSEMBLY (MOTOR) 
    CAUTION: Be sure to wear insulated gloves.
    1. Check that the service plug grip is removed.
    2. Check that the bolts for the three-phase AC cable for Motor are tightened to the specified torque.

      Torque: 10 N*m (102 kgf*cm, 7 ft.*lbf) 

    Fig 3: Checking W/Converter Inverter Assembly Bolts
    G04112045Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: TIGHTEN THEM TO SPECIFIED TORQUE 

    OK: GO TO NEXT STEP 

  5. CHECK CONNECTION CONDITION OF MOTOR RESOLVER CONNECTOR 
    1. Check the connection of the motor resolver connector.

      OK: 

      Connector is connected securely and there is no poor connection. 

    Fig 4: Checking Connection Condition Of Motor Resolver Connector
    G04112046Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: CONNECT SECURELY 

    OK: GO TO NEXT STEP 

  6. HARNESS AND CONNECTOR (MG ECU - MOTOR RESOLVER) 
    1. Disconnect the I22 MG ECU connector.
    2. Disconnect the M14 motor resolver connector.
    3. Measure the voltage according to the value(s) in the table below when the ignition switch is in the ON position.

      Standard Voltage 

      MG ECU - MOTOR RESOLVER

      Tester Connection Specified Condition
      MRF (I22-13) - Body ground Below 1 V
      MRFG (I22-23) - Body ground Below 1 V
      MSN (I22-21) - Body ground Below 1 V
      MSNG (I22-20) - Body ground Below 1V
      MCS (I22-19) - Body ground Below 1 V
      MCSG (I22-18) - Body ground Below 1 V
    4. Turn the ignition switch off.
    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for open) 

      MG ECU - MOTOR RESOLVER (CHECK FOR OPEN)

      Tester Connection Specified Condition
      MRF (I22-13) - MRF (M14-1) Below 1 Ω
      MRFG (I22-23) - MRFG (M14-4) Below 1 Ω
      MSN (I22-21) - MSN (M14-2) Below 1 Ω
      MSNG (I22-20) - MSNG (M14-5) Below 1 Ω
      MCS (I22-19) - MCS (M14-3) Below 1 Ω
      MCSG (I22-18) - MCSG (M14-6) Below 1 Ω

      Standard Resistance (Check for short) 

      MG ECU - MOTOR RESOLVER (CHECK FOR SHORT)

      Tester Connection Specified Condition
      MRF (I22-13) or MRF (M14-1) - Body ground 10 kΩ or higher
      MRFG (I22-23) or MRFG (M14-4) - Body ground 10 kΩ or higher
      MSN (I22-21) or MSN (M14-2) - Body ground 10 kΩ or higher
      MSNG (I22-20) or MSNG (M14-5) - Body ground 10 kΩ or higher
      MCS (I22-19) or MCS (M14-3) - Body ground 10 kΩ or higher
      MCSG (I22-18) or MCSG (M14-6) - Body ground 10 kΩ or higher
      Fig 5: Checking Harness And Connector (MG ECU - Motor Resolver)
      G04112047Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY 

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

scientia non olet · About LEMON Manuals