RX400h · Service Manual HYBRID SYSTEM

P0A91-705

Diagnostic trouble codes

DESCRIPTION

Refer to the description of the Motor. (Click here)
DTC No.
 INF Code
 DTC Detection Condition
 Trouble Area
P0A91
 705
 Rear Motor magnetic force deterioration or same phase short circuit
  1. Wire harness or connector
  2. Rear traction motor w/ transaxle assembly
  3. Frame wire No.3
  4. Extension wire assembly
  5. w/ converter inverter assembly (MG ECU)

MONITOR DESCRIPTION

The MG ECU monitors the hybrid vehicle rear motor. If the MG ECU detects a reduction in the magnetic force of the Rear Motor or an in-phase short, it interprets this as a Rear Motor failure. The HV control ECU then 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
    P0A1A (all details), P0A1B (all details), P0A1C (all details)
    		 MG ECU circuit malfunction
    P0A1D (all details)
    		 HV ECU circuit malfunction
    P0A3F-243, P0A40-500, P0A41-245
    		 Motor resolver circuit malfunction
    P0A45-669, P0A46-671, P0A47-670
    		 Rear motor resolver circuit malfunction
    P0A4B-253, P0A4C-513, P0A4D-255
    		 Generator resolver circuit malfunction
    P0A51-174, P0A55-687
    		 MG ECU circuit malfunction
    P0A60 (all details), P0A63 (all details)
    		 Motor current sensor circuit
    P0A69 (all details), P0A6C (all details)
    		 Rear motor current sensor circuit
    P0A72 (all details), P0A75 (all details)
    		 Generator current sensor circuit
    P0A78-306, 510, 508, 586, 266, 272, 280, 304, 267, 278, 283, 285, 305, 523
    		 Motor inverter function malfunction
    P0A79-703, 704, 701, 672, 690, 691, 697, 698
    		 Rear motor inverter function malfunction
    P0A7A-344, 522, 520, 309, 321, 323, 342, 343
    		 Generator inverter function malfunction
    P0A90-509
    		 Motor function malfunction
    P0A91-702
    		 Rear motor function malfunction
    P0A92-521
    		 Generator function malfunction
    P0A94-585, 587, 561, 551, 588, 589, 545, 546, 552, 558, 559, 583, 584, 590
    		 Boost converter circuit
    P0AA6 (all details), P3004-132
    		 High-voltage system
    P3232-749, P3233-750
    		 HV gate shutdown wiring 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. P0A91-705 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. REPRODUCTION TEST

  1. Connect the intelligent tester to the DLC3.

  1. Test-drive the vehicle at a speed of 40 km/h for approximately 1 minute.

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

  1. Read output DTCs. (Click here)


Result:
DTC output.
 Proceed to
P0A79-704 or P0A91-702 is output
 A
P0A91-705 is output or no DTC is output
 B



A
GO TO DTC CHART
B


3. CHECK REAR TRACTION MOTOR W/TRANSAXLE ASSEMBLY

CAUTION:
Be sure to wear insulated gloves.

  1. A105187E01
    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. Check that the bolts for the three-phase AC cable of the rear traction motor w/ transaxle assembly are tightened to the specified torque.

Torque:
15 N*m{ 153 kgf*cm , 11 ft.*lbf }



NG
TIGHTEN THEM TO SPECIFIED TORQUE
OK


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

CAUTION:
Be sure to wear insulated gloves.

  1. Check that the service plug grip is removed.

  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. A103665E01
    Check the connections of the MG ECU connectors.

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



 NG
CONNECT SECURELY
OK


5. 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 of the rear traction motor w/ transaxle assembly are tightened to the specified torque.

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



NG
TIGHTEN THEM TO SPECIFIED TORQUE
OK


6. CHECK FRAME WIRE NO.3

CAUTION:
Be sure to wear insulated gloves.

  1. A109645E04
    Turn the ignition switch off and remove the service plug grip.

    NOTICE:
    Do not put the vehicle into the READY-on state with the service plug grip removed as this may cause a malfunction.

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

  1. A105214E02
    Disconnect the three-phase AC cable for Rear Motor from the w/ converter inverter assembly.

  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 FRAME WIRE NO.3
OK


7. 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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