HYBRID CONTROL SYSTEM, Diagnostic DTC:P0731-873

DTC Code DTC Name
P0731-873 Gear 1 Incorrect Ratio

DESCRIPTION

Refer to the description for DTC P0731-871 Click here.

Tech Tips

Although the DTC title indicates an incorrect gear ratio, this DTC relates to a malfunction of the B2 hydraulic circuit.

DTC No. INF Code DTC Detection Condition Trouble Area
P0731 873 After DTC P0868 is detected, the power management control ECU cannot confirm that the fluid pressure is forcibly applied to the B2 circuit.

  • Hybrid vehicle transmission assembly

  • Power management control ECU

  • Wire harness or connector

WIRING DIAGRAM

Refer to the wiring diagram for DTC P0731-871 Click here.

PROCEDURE


  1. CHECK DTC OUTPUT (HYBRID CONTROL)


    1. Connect the GTS 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
      P0731-873 only is output. A
      Any of the following DTCs are also output. B
      DTC No. Relevant Diagnosis
      P0748-850 Pressure Control Solenoid "A" Electrical (Shift Solenoid Valve (SL1))
      P0778-851 Pressure Control Solenoid "B" Electrical (Shift Solenoid Valve (SL2))

    5. Turn the power switch off.


    B

    GO TO DTC CHART (HYBRID CONTROL SYSTEM) Click here

    A

  2. CHECK CONNECTOR CONNECTION CONDITION (POWER MANAGEMENT CONTROL ECU CONNECTOR)


    1. B002B9CE01
      Text in Illustration
      *A for LHD
      *B for RHD

      Check the connector connections and contact pressure of the relevant terminals for the power management control ECU connectors Click here.

      OK
      The connectors are connected securely and there are no contact pressure problems.

    NG

    CONNECT SECURELY

    OK

  3. CHECK CONNECTOR CONNECTION CONDITION (TRANSMISSION WIRE CONNECTOR)


    1. A000SJ3

      Check the connection of the transmission wire connector Click here.

      OK
      The connector is connected securely and there are no contact problems.

    NG

    CONNECT SECURELY

    OK

  4. CHECK HYBRID VEHICLE TRANSMISSION ASSEMBLY (SOLENOID VALVE (SL1), SOLENOID VALVE (SL2))


    1. A000RZYE02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Disconnect the connector from the power management control ECU.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      N91-14 (SL1+) - N91-13 (SL1-) 68°F (20°C) 5.0 to 5.6 Ω
      N91-12 (SL2+) - N91-11 (SL2-) 68°F (20°C) 5.0 to 5.6 Ω

    3. Connect the power management control ECU connector.


    NG

    CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - TRANSMISSION WIRE) Click here

    OK

  5. CLEAR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

    4. Read and record the DTCs and freeze frame data.

    5. Clear DTCs and freeze frame data.

    6. Turn the power switch off.


    NEXT

  6. SIMULATION TEST


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / Active Test / Activate the Oil Pump (500rpm), Activate the Oil Pump (1000rpm).

    4. Select OPM Revolution in the Data List.

    5. Perform the "Activate the Oil Pump (500rpm)" and "Activate the Oil Pump (1000rpm)" Active Tests.

      OK
      For both the "Activate the Oil Pump (500rpm)" and "Activate the Oil Pump (1000rpm)" Active Tests, the value of "OPM Revolution" is almost the same as the corresponding Active Test speed.

      Note

      Make sure that the auxiliary battery is not discharged.

    6. Turn the power switch off.


    NG

    REPLACE HYBRID VEHICLE TRANSMISSION ASSEMBLY Click here

    OK

  7. CHECK FOR INTERMITTENT PROBLEMS

    Click here


    NG

    REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA

    OK

  8. CHECK FLUID LEAKS


    1. Check for fluid leaks from the hybrid vehicle transmission assembly.

      OK
      There are no fluid leaks.

    OK

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    NG

    REPAIR OR REPLACE HYBRID VEHICLE TRANSMISSION ASSEMBLY Click here

  9. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - TRANSMISSION WIRE)


    1. A000O1WE02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)
      *b

      Front view of wire harness connector

      (to Transmission Wire)

      Disconnect the transmission wire connector.

    2. Disconnect the connector from the power management control ECU.

    3. Turn the power switch on (IG).

    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A36-6 (PB1) - Body ground Power switch on (IG) Below 1 V

      Note

      Turning the power switch on (IG) with the power management control ECU connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

    5. Turn the power switch off.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A36-6 (PB1) - F52-11 (PB1) Power switch off Below 1 Ω
      A36-6 (PB1) or F52-11 (PB1) - Body ground and other terminals Power switch off 10 kΩ or higher

    7. Connect the transmission wire connector.

    8. Connect the power management control ECU connector.


    OK

    REPLACE HYBRID VEHICLE TRANSMISSION ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR