СИСТЕМА АВТОМАТИЧЕСКОЙ ТРАНСМИССИИ, Diagnostic DTC:P0756

Информация добавлена 08-08-2017

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, gear, etc.).

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P0756 Shift Solenoid "B" Performance (Shift Solenoid Valve S2) Gear required by ECM does not match actual gear when driving (2-trip detection logic).

  • 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.)

 Comes on DTC stored

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.

CAUTION / NOTICE / HINT


  1. ACTIVE TEST

    Tech Tips

    Using the GTS 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 engine switch off.

    3. Connect the GTS to the DLC3.

    4. Turn the engine switch on (IG).

    5. Turn the GTS on.

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

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

      Tech Tips

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

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


      Powertrain > Engine and ECT > Active Test
      Tester Display
      Control the Shift Position

      Powertrain > Engine and ECT > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Control the Shift Position Operate shift solenoid valve 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 ECM is shown in the Data List display on the GTS.

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

        ECM 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 GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.


      Powertrain > Engine and ECT > Trouble Codes

    5. Read the DTCs using the GTS.

      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

    GO TO DTC CHART Click here

    A

  2. PERFORM ACTIVE TEST USING GTS (SHIFT SOLENOID VALVE SLT)

    Note


    • Perform the test while the ATF temperature is 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

    Using the GTS to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can bevery 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. A01A5SDN04

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

      SST
      09992-00095   ( 09992-00231, 09992-00271 )

    2. Connect the GTS to the DLC3.

    3. Start the engine and warm it up.

    4. Measure the line pressure with SST.

    5. Turn the GTS on.

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

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

    8. Measure the line pressure.


      Powertrain > Engine and ECT > Active Test
      Tester Display
      Activate the Solenoid (SLT)

      Powertrain > Engine and ECT > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Activate the Solenoid (SLT) Operate shift solenoid SLT and raise line pressure

      ON or OFF

      Tech Tips


      • OFF: Line pressure up (when Active Test "Activate the Solenoid (SLT)" is performed, ECM commands SLT solenoid 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.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE SHIFT SOLENOID VALVE SLT Click here

    OK

  3. INSPECT SHIFT SOLENOID VALVE S2


    1. Remove shift solenoid valve S2.

    2. A01A466C01
      *a

      Component without harness connected

      (Shift Solenoid Valve S2)

      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 operating noise
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE SHIFT SOLENOID VALVE S2 Click here

    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.
      Result
      Proceed to
      OK
      NG

    OK

    REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY Click here

    NG

    REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY Click here