RX400h · Service Manual HYBRID SYSTEM

P0A79-693

Diagnostic trouble codes

DESCRIPTION

Refer to the description of the inverter. (Click here)
If the rear motor inverter circuit is opened or shorted, or if the circuit overheats, the information is transmitted from the inverter to the RFIV terminal of the MG ECU via the rear motor inverter fail signal line.
DTC No.
 INF Code
 DTC Detection Condition
 Trouble Area
P0A79
 693
 Rear motor inverter fail signal detection
(overcurrent by inverter assembly malfunction)
  1. Wire harness or connector
  2. Rear traction motor w/ transaxle assembly
  3. Frame wire No.3
  4. w/ converter inverter assembly (MG ECU)
  5. Extension wire assembly
↑
 694
 Rear motor inverter fail signal detection
(overcurrent by MG ECU malfunction)
  1. Wire harness or connector
  2. Rear traction motor w/ transaxle assembly
  3. Frame wire No.3
  4. w/ converter inverter assembly (MG ECU)
  5. Extension wire assembly

MONITOR DESCRIPTION

If over-amperage flows through the rear motor inverter due to an internal short, the rear motor inverter transmits an inverter fail signal to the MG ECU. Upon receiving this signal, 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.

  1. Turn the ignition switch to the ON position.

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

  1. Read output DTCs. (Click here)

    Result:
    The DTCs shown in the table below are output:
    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
    		 Motor inverter function malfunction
    P0A7A
    		 Generator inverter function malfunction
    P0A90
    		 Motor function malfunction
    P0A92
    		 Generator function malfunction
    P0A93
    		 Inverter cooling system
    P0A94 (Except for 554 and 555)
    		 Boost converter circuit
    P0AA1, P0AA2, P0AA4, P0AA5
    		 System main relay circuit
    P3004, P0AA6
    		 High-voltage system
    P0A79 (Except for 693, 694, 812, 813, and 814)
    		 Rear motor inverter function malfunction
    P0A45, P0A46, P0A47
    		 Rear motor resolver malfunction
    P0A69, P0A6C, P0A55
    		 Rear motor current sensor circuit
    P0A1A, P0A1B, P0A1C
    		 MG ECU circuit 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. P0A79-693 and P0A78-694 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. CONNECTION CONDITION OF HV CONTROL ECU CONNECTOR (LOOSENESS AND POOR CONTACT)

  1. A103658E18
    Check the connections of the HV control ECU connectors.

    OK:
    Connectors are connected securely and there is no poor connection.



 NG
CONNECT SECURELY
OK


3. CHECK CONNECTION CONDITION OF MG ECU CONNECTOR (LOOSENESS AND POOR CONTACT)

CAUTION:
Be sure to wear insulated gloves.

  1. A103665E01
    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.

  1. 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.

  1. Check the connections of the MG ECU connectors.

    OK:
    Connectors are connected securely and there is no poor connection.



 NG
CONNECT SECURELY
OK


4. CHECK W/ CONVERTER INVERTER ASSEMBLY (REAR MOTOR)

CAUTION:
Be sure to wear insulated gloves.

  1. A105182
    Check that the service plug grip is removed.

  1. Check that the bolts for the three-phase AC cable for Rear Motor are tightened to the specified torque.

Torque:
10 N*m{ 102 kgf*cm , 7 ft.*lbf }



NG
TIGHTEN THEM TO SPECIFIED TORQUE
OK


5. INSPECT REAR TRACTION MOTOR W/TRANSAXLE ASSEMBLY

CAUTION:
Be sure to wear insulated gloves.

  1. Check that the service plug grip is removed.

  1. A109645E04
    Disconnect the three-phase AC cable of the rear traction motor w/ transaxle assembly from the inverter.

  1. A105184E01
    Using a milliohmmeter, measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    U - V
    		 109 mΩ or less (20°C)
    V - W
    		 109 mΩ or less (20°C)
    W - U
    		 109 mΩ or less (20°C)

    NOTICE:
    If the Rear Motor temperature is too high, the resistance changes greatly. Therefore, measure the resistance at least 8 hours after the vehicle is stopped.

  1. To correct the resistance varying depending on the temperature, use the following formula to calculate the resistance at 20°C.

    HINT:
    1. R20 = Rt / {1 + 0.00393 X (T - 20)}
    2. R20: Resistance at 20 °C(mΩ)
    3. Rt: Measured resistance (mΩ)
    4. T: Temperature when the resistance is measured (°C)

  1. Calculate the difference between the maximum and minimum resistance.

    Standard resistance:
    Difference is 5 mΩ or less

  1. Using a megohmmeter, measure the insulation resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    U - Body ground
    		 10 MΩ or higher
    V - Body ground
    		 10 MΩ or higher
    W - Body ground
    		 10 MΩ or higher



NG
Go to step 8
OK


6. CHECK HARNESS AND CONNECTOR (MG ECU - REAR MOTOR RESOLVER)

  1. A105213E02
    Disconnect the I25 connector from the MG ECU.

  1. Disconnect the M11 rear motor resolver connector.

  1. Measure the voltage according to the value(s) in the table below when the ignition switch is in the ON position.

    Standard Voltage:
    Tester Connection
    		 Specified Condition
    RRF (I25-21) - Body ground
    		 Below 1 V
    RRFG (I25-22) - Body ground
    		 Below 1 V
    RSN (I25-29) - Body ground
    		 Below 1 V
    RSNG (I25-30) - Body ground
    		 Below 1 V
    RCS (I25-11) - Body ground
    		 Below 1 V
    RCSG (I25-23) - Body ground
    		 Below 1 V

    NOTICE:
    Turning the ignition switch to the ON position with the MG ECU connectors disconnected causes other DTCs to be stored. Clear the DTCs after performing the inspection.

  1. Turn the ignition switch off.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance (Check for open):
    Tester Connection
    		 Specified Condition
    RRF (I25-21) - RRF (M11-1)
    		 Below 1 Ω
    RRFG (I25-22) - RRFG (M11-4)
    		 Below 1 Ω
    RSN (I25-29) - RSN (M11-2)
    		 Below 1 Ω
    RSNG (I25-30) - RSNG (M11-5)
    		 Below 1 Ω
    RCS (I25-11) - RCS (M11-3)
    		 Below 1 Ω
    RCSG (I25-23) - RCSG (M11-6)
    		 Below 1 Ω

    Standard Resistance (Check for short):
    Tester Connection
    		 Specified Condition
    RRF (I25-21) or RRF (M11-1) - Body ground
    		 10 kΩ or higher
    RRFG (I25-22) or RRFG (M11-4) - Body ground
    		 10 kΩ or higher
    RSN (I25-29) or RSN (M11-2) - Body ground
    		 10 kΩ or higher
    RSNG (I25-30) or RSNG (M11-5) - Body ground
    		 10 kΩ or higher
    RCS (I25-11) or RCS (M11-3) - Body ground
    		 10 kΩ or higher
    RCSG (I25-23) or RCSG (M11-6) - Body ground
    		 10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


7. INSPECT REAR MOTOR RESOLVER

  1. A083675E05
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    MRF (M11-1) - MRFG (M11-4)
    		 7.65 to 10.2 Ω
    MSN (M11-2) - MSNG (M11-5)
    		 12.6 to 16.8 Ω
    MCS (M11-3) - MCSG (M11-6)
    		 12.6 to 16.8 Ω

  1. Using a megohmmeter, measure the insulation resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    MRF (M11-1) - MSN (M11-2)
    		 10 MΩ or higher
    MRF (M11-1) - MCS (M11-3)
    		 10 MΩ or higher
    MSN (M11-2) - MCS (M11-3)
    		 10 MΩ or higher
    MRFG (M11-4) - MSNG (M11-5)
    		 10 MΩ or higher
    MRFG (M11-4) - MCSG(M11-6)
    		 10 MΩ or higher
    MSNG (M11-5) - MCSG (M11-6)
    		 10 MΩ or higher
    Each terminal listed above - Transaxle housing
    		 10 MΩ or higher



NG
REPLACE REAR TRACTION MOTOR W/TRANSAXLE ASSEMBLY
OK

REPLACE W/ CONVERTER INVERTER ASSEMBLY

8. CHECK FRAME WIRE NO.3

NOTICE:
Be sure to wear insulated gloves.

  1. C105715
    Disconnect the three-phase AC cable for Rear Motor from the rear traction motor w/ transaxle assembly.

  1. A105214E01
    Disconnect the three-phase AC cable from the rear traction motor.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance (Check for open):
    Tester Connection
    		 Specified Condition
    U - U
    		 Continuity
    V - V
    		 Continuity
    W - W
    		 Continuity

    Standard Resistance (Check for short):
    Tester Connection
    		 Specified Condition
    U - V
    		 No continuity
    V - W
    		 No continuity
    W - U
    		 No continuity



NG
REPLACE FRAME WIRE NO.3
OK


9. INSPECT EXTENSION WIRE ASSEMBLY

  1. Remove the rear traction motor w/ transaxle assembly. (Click here)

  1. Remove the extension wire assembly from the rear traction motor w/ transaxle assembly. (Click here)

  1. A112804E01
    Using a megohmmeter, measure the insulation resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    U - Shield shell
    		 10 MΩ or higher
    V - Shield shell
    		 10 MΩ or higher
    W - Shield shell
    		 10 MΩ or higher

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    U - U
    		 Below 1 Ω
    V - V
    		 Below 1 Ω
    W - W
    		 Below 1 Ω



NG
REPLACE EXTENSION WIRE ASSEMBLY
OK

REPLACE REAR TRACTION MOTOR W/TRANSAXLE ASSEMBLY


← P0A79-692P0A79-695 →