ELECTRONIC CONTROLLED AUTOMATIC TRANSMISSION SYSTEM, Diagnostic DTC:P0756

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

DESCRIPTION

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

DTC No. DTC Detection Condition Trouble Area
P0756 Gear required by ECM does not match 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 or gear, etc.)

MONITOR DESCRIPTION

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

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

INSPECTION PROCEDURE

Tech Tips

Performing the intelligent tester's Active Test allows relay, Vacuum Switching Valve (VSV), actuator and other item values to be operated without removing any parts. Performing the Active Test early in troubleshooting is one way to save time. The Data List can be displayed during the Active Test.


  1. Warm up the engine.

  2. Turn the ignition switch OFF.

  3. Connect the intelligent tester to the DLC3.

  4. Turn the ignition switch ON and push the tester main switch ON.

  5. Enter the following menus: Powertrain / Engine and ECT / Active Test.

  6. Follow the instructions on the tester and read 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.

Item Test Details Diagnostic Note
Control the Shift Position

[Test Details]

Operate shift solenoid valve and set each shift position by yourself

[Vehicle Condition]

50 km/h (31 mph) or less

[Other information]


  • Press "→" button: Shift up

  • Press "←" button: Shift down

 Possible to check operation of shift solenoid valves

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 ECM is shown in the Data List (shift status) display on the intelligent tester.

  • The shift solenoid valve S2 is turned ON/OFF normally when the shift lever is on D:

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

PROCEDURE


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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch ON and push the intelligent tester main switch ON.

    3. Enter the following menus: Powertrain / Engine and ECT / DTC / Current or Pending.

    4. Read the DTCs using the intelligent tester.

      Result
      Display (DTC output) Proceed to
      Only P0756 is output A
      P0756 and other DTCs B

      Tech Tips

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


    B

    GO TO DTC CHART

    A

  2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER

    A01E342E01

    Note


    • Perform the test at the normal operating ATF temperature: 50 to 80°C (122 to 176°F).

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

    • Perform the test with the A/C OFF.

    Tech Tips

    Performing the intelligent tester's Active Test allows relay, Vacuum Switching Valve (VSV), actuator and other items values to be operated without removing any parts. Performing the Active Test early in troubleshooting is one way to save time. The Data List can be displayed during the Active Test.


    1. Remove the test plug on the transmission case center right side 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 / Engine and ECT / Active Test.

    7. Follow the instructions on the tester and perform the Active Test.

    8. Measure the line pressure with SST.

      Item Test Details Diagnostic Note
      Control the Line Pressure Up*

      [Test Details]

      Operate shift solenoid SLT and raise line pressure

      [Vehicle Condition]


      • Vehicle stopped

      • IDL: ON

      Tech Tips

      OFF: Line pressure up (when Active Test "Control the Line Pressure Up" is performed, ECM commands SLT solenoid to turn OFF)

      ON: No action (normal operation)

      		 -

      Tech Tips

      *: "Control the Line Pressure Up" 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. Please note that the pressure values in the Active Test and Hydraulic Test are different.


    NG

    REPLACE SHIFT SOLENOID VALVE SLT

    OK

  3. INSPECT SHIFT SOLENOID VALVE S2


    1. A01DXDQE01

      Remove the shift solenoid valve S2.

    2. Measure the resistance between the solenoid valve terminal and solenoid valve body.

      Standard resistance
      11 to 15 Ω at 20°C (68°F)

    3. Connect the battery's positive (+) lead to the terminal of the solenoid connector, and the negative (-) lead to the solenoid body.

    4. Check the operating noise of the solenoid valve.

      OK
      Solenoid makes operating noise.

    NG

    REPLACE SHIFT SOLENOID VALVE S2

    OK

  4. INSPECT TRANSMISSION VALVE BODY ASSEMBLY


    1. Check the transmission valve body assembly.

      OK
      There are no foreign objects on each valve.

    NG

    REPLACE TRANSMISSION VALVE BODY ASSEMBLY

    OK

    REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY