RX400h · Service Manual HYBRID SYSTEM

P0A94-554

Diagnostic trouble codes

DESCRIPTION

Refer to the description of the boost converter. (Click here)
DTC No.
 INF Code
 DTC Detection Condition
 Trouble Area
P0A94
 554
 Boost converter inverter fail signal detection (overcurrent by MG ECU malfunction)
  1. Wire harness or connector
  2. Hybrid vehicle transaxle assembly
  3. Rear traction motor w/ transaxle assembly
  4. w/ converter inverter assembly (MG ECU)
  5. Frame wire No.3
  6. Extension wire assembly
P0A94
 555
 Boost converter inverter fail signal detection (overcurrent by inverter assembly malfunction)
  1. Wire harness or connector
  2. Hybrid vehicle transaxle assembly
  3. Rear traction motor w/ transaxle assembly
  4. w/ converter inverter assembly (MG ECU)
  5. Frame wire No.3
  6. Extension wire assembly

MONITOR DESCRIPTION

If over-amperage flows through the boost converter due to an internal short, the boost converter transmits a boost converter 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 DTC. (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
    P0A94 (Except for 554 and 555)
    		 Boost converter circuit
    P0AA1, P0AA2, P0AA4, P0AA5
    		 System main relay circuit
    P0AA6, P3004
    		 High-voltage system
    P0A79
    		 Rear motor inverter function malfunction
    P0A45, P0A46, P0A47
    		 Rear motor resolver malfunction
    P0A69, P0A6C, P0A55
    		 Rear motor current sensor circuit

    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. P0A94-554 and P0A94-505 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. 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. (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. A103665E03
    Check the connections of the MG ECU connectors.

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



 NG
CONNECT SECURELY
OK


3. INSPECT HYBRID VEHICLE TRANSAXLE ASSEMBLY (MOTOR)

CAUTION:
Be sure to wear insulated gloves.

  1. Check that the service plug grip is removed.

  1. A111754E02
    Disconnect the three-phase AC cable for Motor from the w/ converter inverter assembly.

  1. A111755E02
    Using a milliohmmeter, measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    U - V
    		 48 to 59 mΩ (20°C)
    V - W
    		 48 to 59 mΩ (20°C)
    W - U
    		 48 to 59 mΩ (20°C)

    NOTICE:
    If the 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 and shielded wire ground
    		 10 MΩ or higher
    V - Body ground and shielded wire ground
    		 10 MΩ or higher
    W - Body ground and shielded wire ground
    		 10 MΩ or higher



NG
REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY
OK


4. INSPECT HYBRID VEHICLE TRANSAXLE ASSEMBLY (GENERATOR)

CAUTION:
Be sure to wear insulated gloves.

  1. Check that the service plug grip is removed.

  1. A113849E01
    Disconnect the three-phase AC cable for Generator from the w/ converter inverter assembly.

  1. A111753E02
    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 Generator temperature is too high, the resistance varies 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 3 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 and shielded wire ground
    		 10 MΩ or higher
    V - Body ground and shielded wire ground
    		 10 MΩ or higher
    W - Body ground and shielded wire ground
    		 10 MΩ or higher



NG
REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY
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. A109645E05
    Disconnect the three-phase AC cable for Rear Motor from the w/ converter inverter assembly.

  1. A105184E02
    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 varies 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 and shielded wire ground
    		 10 MΩ or higher
    V - Body ground and shielded wire ground
    		 10 MΩ or higher
    W - Body ground and shielded wire ground
    		 10 MΩ or higher



NG
Go to step 12
OK


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

CAUTION:
Be sure to wear insulated gloves.

  1. Check that the service plug grip is removed.

  1. A103666E04
    Disconnect the I24 connector from the MG ECU.

  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
    MRF (I24-13) - Body ground
    		 Below 1 V
    MRFG (I24-23) - Body ground
    		 Below 1 V
    MSN (I24-21) - Body ground
    		 Below 1 V
    MSNG (I24-20) - Body ground
    		 Below 1 V
    MCS (I24-19) - Body ground
    		 Below 1 V
    MCSG (I24-18) - 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:
    Tester Connection
    		 Specified Condition
    MRF (I24-13) - MRFG (I24-23)
    		 7.65 to 10.2 Ω
    MSN (I24-21) - MSNG (I24-20)
    		 12.6 to 16.8 Ω
    MCS (I24-19) - MCSG (I24-18)
    		 12.6 to 16.8 Ω

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

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    MRF (I24-13) or MRFG (I24-23) - Body ground
    		 10 kΩ or higher
    MSN (I24-21) or MSNG (I24-20) - Body ground
    		 10 kΩ or higher
    MCS (I24-19) or MCSG (I24-18) - Body ground
    		 10 kΩ or higher



NG
Go to step 9
OK


7. CHECK HARNESS AND CONNECTOR (MG ECU - GENERATOR RESOLVER)

CAUTION:
Be sure to wear insulated gloves.

  1. Check that the service plug grip is removed.

  1. A103666E03
    Disconnect the I24 connector from the MG ECU.

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

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    GRF (I24-12) - Body ground
    		 Below 1 V
    GRFG (I24-22) - Body ground
    		 Below 1 V
    GSN (I24-11) - Body ground
    		 Below 1 V
    GSNG (I24-10) - Body ground
    		 Below 1 V
    GCS (I24-9) - Body ground
    		 Below 1 V
    GCSG (I24-8) - 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:
    Tester Connection
    		 Specified Condition
    GRF (I24-12) - GRFG (I24-22)
    		 7.65 to 10.2 Ω
    GSN (I24-11) - GSNG (I24-10)
    		 12.6 to 16.8 Ω
    GCS (I24-9) - GCSG (I24-8)
    		 12.6 to 16.8 Ω

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

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    GRF (I24-12) or GRFG (I24-22) - Body ground
    		 10 kΩ or higher
    GSN (I24-11) or GSNG (I24-10) - Body ground
    		 10 kΩ or higher
    GCS (I24-9) or GCSG (I24-8) - Body ground
    		 10 kΩ or higher



NG
Go to step 10
OK


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

CAUTION:
Be sure to wear insulated gloves.

  1. Check that the service plug grip is removed.

  1. A103667E04
    Disconnect the I25 connector from the MG ECU.

  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:
    Tester Connection
    		 Specified Condition
    RRF (I25-21) - RRFG (I25-22)
    		 7.65 to 10.2 Ω
    RSN (I25-29) - RSNG (I25-30)
    		 12.6 to 16.8 Ω
    RCS (I25-11) - RCSG (I25-23)
    		 12.6 to 16.8 Ω

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

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    RRF (I25-21) or RRFG (I25-22) - Body ground
    		 10 kΩ or higher
    RSN (I25-29) or RSNG (I25-30) - Body ground
    		 10 kΩ or higher
    RCS (I25-11) or RCSG (I25-23) - Body ground
    		 10 kΩ or higher



NG
Go to step 11
OK

REPLACE W/ CONVERTER INVERTER ASSEMBLY

9. INSPECT MOTOR RESOLVER

  1. A105165
    Disconnect the M7 motor resolver connector.

  1. A083675E04
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    MRF (M7-1) - MRFG (M7-4)
    		 7.65 to 10.2 Ω
    MSN (M7-2) - MSNG (M7-5)
    		 12.6 to 16.8 Ω
    MCS (M7-3) - MCSG (M7-6)
    		 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 (M7-1) - MSN (M7-2)
    		 10 MΩor higher
    MRF (M7-1) - MCS (M7-3)
    		 10 MΩor higher
    MSN (M7-2) - MCS (M7-3)
    		 10 MΩor higher
    MRFG (M7-4) - MSNG (M7-5)
    		 10 MΩor higher
    MRFG (M7-4) - MCSG(M7-6)
    		 10 MΩor higher
    MSNG (M7-5) - MCSG (M7-6)
    		 10 MΩor higher
    Each terminal listed above - Transaxle housing
    		 10 MΩor higher



NG
REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY
OK

REPAIR OR REPLACE HARNESS OR CONNECTOR

10. INSPECT GENERATOR RESOLVER

  1. Remove the w/ converter inverter assembly.

  1. A105167
    Disconnect the M6 generator resolver connector.

  1. A105163E02
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    GRF (M6-1) - GRFG (M6-6)
    		 7.65 to 10.2 Ω
    GSN (M6-2) - GSNG (M6-7)
    		 12.6 to 16.8 Ω
    GCS (M6-3) - GCSG (M6-8)
    		 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
    GRF (M6-1) - GSN (M6-2)
    		 10 MΩ or higher
    GRF (M6-1) - GCS (M6-3)
    		 10 MΩ or higher
    GSN (M6-2) - GCS (M6-3)
    		 10 MΩ or higher
    GRFG (M6-6) - GSNG (M6-7)
    		 10 MΩ or higher
    GRFG (M6-6) - GCSG (M6-8)
    		 10 MΩ or higher
    GSNG (M6-7) - GCSG (M6-8)
    		 10 MΩ or higher
    Each terminal listed above - Transaxle housing
    		 10 MΩ or higher



NG
REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY
OK

REPAIR OR REPLACE HARNESS OR CONNECTOR

11. INSPECT REAR MOTOR RESOLVER

  1. A105166
    Disconnect the M11 rear motor resolver connector.

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

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    RRF (M11-1) - RRFG (M11-4)
    		 7.65 to 10.2 Ω
    RSN (M11-2) - RSNG (M11-5)
    		 12.6 to 16.8 Ω
    RCS (M11-3) - RCSG (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
    RRF (M11-1) - RSN (M11-2)
    		 10 MΩ or higher
    RRF (M11-1) - RCS (M11-3)
    		 10 MΩ or higher
    RSN (M11-2) - RCS (M11-3)
    		 10 MΩ or higher
    RRFG (M11-4) - RSNG (M11-5)
    		 10 MΩ or higher
    RRFG (M11-4) - RCSG (M11-6)
    		 10 MΩ or higher
    RSNG (M11-5) - RCSG (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

REPAIR OR REPLACE HARNESS OR CONNECTOR

12. INSPECT FRAME WIRE NO.3

CAUTION:
Be sure to wear insulated gloves.

  1. Check that the service plug grip is removed.

  1. C105715
    Disconnect the frame wire No.3 from the rear traction motor w/ transaxle assembly.

  1. A105214E02
    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 and shielded wire ground
    		 10 MΩ or higher
    V - Body ground and shielded wire ground
    		 10 MΩ or higher
    W - Body ground and shielded wire ground
    		 10 MΩ or higher

    NOTICE:
    Wrap the terminals U, V and W of the w/ converter inverter assembly side No.3 wire frame (three-phase AC cable of the rear traction motor w/ transaxle assembly) with the insulating tape to prevent them from shorting to ground.

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

    Standard Resistance:
    Tester Connection
    		 Specified Condition
    U - V
    		 10 kΩ or higher
    U - W
    		 10 kΩ or higher
    V - W
    		 10 kΩ or higher



NG
REPLACE FRAME WIRE NO.3
OK


13. 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


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