AUTOMATIC TRANSMISSION SYSTEM (for 1KD-FTV), Diagnostic DTC:P0756

DTC Code DTC Name
P0756 Shift Solenoid "B" Performance (Shift Solenoid Valve S2)

DESCRIPTION

The TCM uses signals from the output shaft speed sensor and input speed sensor to detect the actual gear position (1st, 2nd, 3rd, 4th or 5th gear).

Then the TCM compares the actual gear with the shift schedule in the TCM memory to detect mechanical problems of the shift solenoid valves, valve body or automatic transmission (clutch, brake, gear, etc.).

DTC Code DTC Detection Condition Trouble Area
P0756 Gear required by the TCM does not match the actual gear when driving (2-trip detection logic*1, 1-trip detection logic*2).
  • Shift solenoid valve S2 remains open or closed

  • Shift solenoid valve SLT remains open or closed

  • Valve body is blocked

  • Automatic transmission (clutch, brake, gear, etc.)

*1: w/ OBD

*2: w/o OBD

MONITOR DESCRIPTION

This DTC indicates a stuck ON malfunction or stuck OFF malfunction of shift solenoid valve S2.

The TCM commands gear shifts by turning the shift solenoid valves ON/OFF. When the gear position commanded by the TCM and the actual gear position are not the same, the TCM illuminates the MIL and stores the DTC.

INSPECTION PROCEDURE


  1. ACTIVE TEST

    Tech Tips

    Using the intelligent tester to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.


    1. Warm up the engine.

    2. Turn the ignition switch off.

    3. Connect the intelligent tester to the DLC3.

    4. Turn the ignition switch to ON.

    5. Turn the intelligent tester on.

    6. Enter the following menus: Powertrain / ECT / Active Test.

    7. According to the display on the tester, perform the Active Test.

      Tech Tips

      While driving, the shift position can be forcibly changed with the intelligent tester.

      Comparing the shift position commanded by the Active Test with the actual shift position enables you to confirm the problem Click here.

      ECT
      Tester Display Test Part Control Range Diagnostic Note
      Control the Shift Position Operate shift solenoid valves and set each shift position
      • Press "→" button: Shift up

      • Press "←" button: Shift down

      Possible to check operation of the shift solenoid valves.

      [Vehicle Condition]

      50 km/h (31 mph) or less

      Tech Tips


      • This test can be conducted when the vehicle speed is 50 km/h (31 mph) or less.

      • The 4th to 5th up-shift must be performed with the accelerator pedal released.

      • The 5th to 4th down-shift must be performed with the accelerator pedal released.

      • Do not operate the accelerator pedal for at least 2 seconds after shifting and do not shift successively.

      • The shift position commanded by the TCM is shown in the Data List display on the tester.

      • Shift solenoid valve S2 is turned ON/OFF normally when the shift lever is in D.

        TCM gear shift command 1st 2nd 3rd 4th 5th
        Shift solenoid valve S2 OFF ON ON OFF OFF

PROCEDURE


  1. CHECK DTC OUTPUT (IN ADDITION TO DTC P0756)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

    4. Enter the following menus: Powertrain / ECT / DTC.

    5. Read the DTCs using the tester.

      Result
      Result Proceed to
      Only P0756 is output A
      P0756 and other DTCs are output B

      Tech Tips

      If any other codes besides P0756 are output, perform troubleshooting for those DTCs first.


    B
    A
  2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (SHIFT SOLENOID VALVE SLT)

    Note


    • Perform the test while the ATF temperature is between 50 and 80°C (122 and 176°F).

    • Be careful to prevent the hose of SST from interfering with the exhaust pipe.

    • Perform the test with the A/C off.

    Tech Tips

    Using the intelligent tester to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.


    1. A00XH1DE01

      Remove the test plug from the transmission case and connect SST.

      SST
      09992-00095   ( 09992-00231, 09992-00271 )
    2. Connect the intelligent tester to the DLC3.

    3. Start the engine and warm it up.

    4. Measure the line pressure with SST.

    5. Turn the intelligent tester on.

    6. Enter the following menus: Powertrain / ECT / Active Test.

    7. According to the display on the tester, perform the Active Test.

    8. Measure the line pressure.

      ECT
      Tester Display Test Part Control Range Diagnostic Note
      Activate the Solenoid (SLT)* Operate shift solenoid valve SLT and raise line pressure

      ON or OFF

      Tech Tips


      • OFF: Line pressure up (when Active Test "Activate the Solenoid (SLT)" is performed, TCM commands shift solenoid valve SLT to turn OFF)

      • ON: No action (normal operation)

      [Vehicle Condition]


      • Vehicle stopped

      • Engine idling

      Tech Tips

      *: Activate the Solenoid (SLT) in the Active Test is performed to check the line pressure changes by connecting SST to the automatic transmission, which is used in the Hydraulic Test Click here as well. Note that the pressure values in the Active Test and hydraulic test are different.

      OK
      The line pressure changes as specified when performing the Active Test.

    NG
    OK
  3. INSPECT SHIFT SOLENOID VALVE S2


    1. A00XGT7E01
      Text in Illustration
      *a

      Component without harness connected

      (Shift Solenoid Valve S2)

      Remove shift solenoid valve S2.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Shift solenoid valve S2 connector terminal - Shift solenoid valve S2 body 20°C (68°F) 11 to 15 Ω
    3. Apply 12 V battery voltage to the shift solenoid valve and check that the valve moves and makes an operating noise.

      OK
      Measurement Condition Specified Condition

      • Battery positive (+) → Shift solenoid valve S2 connector

      • Battery negative (-) → Shift solenoid valve S2 body

      Valve moves and makes an operating noise

    NG
    OK
  4. INSPECT TRANSMISSION VALVE BODY ASSEMBLY


    1. Check the transmission valve body assembly Click here.

      OK
      There are no foreign objects on any valve.

    NG
    OK