AUTOMATIC TRANSMISSION SYSTEM, Diagnostic DTC:P0766, P0776

DTC Code DTC Name
P0766 Shift Solenoid "D" Performance (Shift Solenoid Valve S4)
P0776 Pressure Control Solenoid "B" Performance (Shift Solenoid Valve SL2)

DESCRIPTION

The ECM uses signals from the transmission revolution sensor (SP2) and transmission revolution sensor (NT) to detect the actual gear position (1st, 2nd, 3rd, 4th, 5th or 6th 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. Detection Item DTC Detection Condition Trouble Area MIL Memory
P0766 Shift Solenoid "D" Performance (Shift Solenoid Valve S4)

S4 stuck OFF malfunction or brake control valve malfunction*:

Shifting to 5th and 6th gears is impossible.

The ECM determines there is a malfunction when the following conditions are both met.(2-trip detection logic)


  • (a) When the ECM directs the gearshift to change to 5th gear, the actual gear is shifted to 4th.

  • (b) When the ECM directs the gearshift to change to 6th gear, the actual gear is shifted to 4th.

  • Shift solenoid valve S4 remains closed

  • Shift solenoid valve SLT remains open or closed

  • Valve body is blocked (Brake control valve)

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

 Comes on DTC stored
P0776 Pressure Control Solenoid "B" Performance (Shift Solenoid Valve SL2)

SL2 stuck ON malfunction or brake control valve malfunction*:

Shifting to 5th and 6th gears is impossible.

The ECM determines there is a malfunction when the following conditions are both met.(2-trip detection logic)


  • (a) When the ECM directs the gearshift to change to 5th gear, the actual gear is shifted to 4th.

  • (b) When the ECM directs the gearshift to change to 6th gear, the actual gear is shifted to 4th.

  • Shift solenoid valve SL2 remains open

  • Shift solenoid valve SLT remains open or closed

  • Valve body is blocked (Brake control valve)

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

 Comes on DTC stored

Tech Tips


  • Gear positions in the event of a solenoid valve mechanical problem:

    ECM commanded gear 1st 2nd 3rd 4th 5th 6th
    *: Actual gear position under malfunction 1st 2nd 3rd 4th 4th 4th

  • Gear position during fail-safe operation:

    If any malfunction is detected, the ECM changes into the fail-safe mode to shift into the gear positions as shown in the table below.

    Gear position under normal conditions 1st 2nd 3rd 4th 5th 6th
    *: Actual gear position under fail-safe mode 1st 2nd 3rd 3rd 3rd 3rd

MONITOR DESCRIPTION

This DTC indicates "stuck OFF malfunction" of the shift solenoid valve S4, "stuck ON malfunction" of the shift solenoid valve SL2, or brake control valve malfunction. 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 same, the ECM illuminates the MIL and stores the DTC.

CAUTION / NOTICE / HINT

Note

Perform registration and/or initialization when parts related to the automatic transmission are replaced.

Click here


  1. ACTIVE TEST

    Tech Tips

    Using the GTS to perform Active Test 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 Test early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Test.


    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 / Control the Shift Position.

    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 enables you to confirm the problem.

      Click here


      Powertrain > Engine > Active Test
      Tester Display Measurement Item 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 (30 mph) or less

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

      Tech Tips


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

      • The 4th to 5th and 5th to 6th up-shifts must be performed with the accelerator pedal released.

      • The 6th to 5th and 5th to 4th down-shifts 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 GTS.

      • The shift solenoid valve S4 and SL2 are turned on/off normally when the shift lever is in the D position:

        ECM commanded gear 1st 2nd 3rd 4th 5th 6th
        Shift solenoid valve S4 OFF OFF OFF OFF ON ON
        Shift solenoid valve SL2 ON ON ON ON OFF OFF

PROCEDURE


  1. CHECK OTHER DTCS OUTPUT


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

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


      Powertrain > Engine > Trouble Codes

    4. Read the DTCs using the GTS.

      Result
      Result Proceed to
      Only P0766 and P0776 are output A
      P0766, P0776 and other DTCs are output B

      Tech Tips

      If any DTCs other than P0766 and P0776 are output, perform troubleshooting for those DTCs first.


    B

    GO TO DTC CHART Click here

    A

  2. PERFORM ACTIVE TEST USING GTS

    Note


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

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

    • This check must be conducted after checking and adjusting engine.

    • Perform under condition that A/C is OFF.

    Tech Tips

    Using the GTS to perform Active Test 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 Test early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Test.


    1. Turn the engine switch off.

    2. Lift the vehicle up.

    3. Remove the test plug on the transmission case center right side and connect SST.

      A01MUHTE01
      SST
      09992-00095   ( 09992-00231, 09992-00271 )

    4. Lower the vehicle.

    5. Fully apply the parking brake and chock the 4 wheels.

    6. Connect the GTS to the DLC3.

    7. Start the engine.

    8. Warm up the ATF (Automatic Transmission Fluid).

    9. Measure the line pressure when the engine is idling.

    10. Turn the GTS on.

    11. Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the Solenoid (SLT).

    12. According to the display on the GTS, perform the "Active Test".

    13. Measure the line pressure with SST.


      Powertrain > Engine > Active Test
      Tester Display Measurement Item 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)" performed, ECM commands shift solenoid valve SLT to turn off)

      • ON: No action (normal operation)

      [Vehicle Condition]


      • IG ON

      • Engine idling

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

      "Activate the Solenoid (SLT)" in the Active Test is performed to check the line pressure changes by connecting the SST to the automatic transmission, which is used in the HYDRAULIC TEST as well.

      Click here

      Tech Tips

      The pressure values in Active Test and HYDRAULIC TEST are different from each other.

      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 S4


    1. A01MYWWC06
      *a Shift Solenoid Valve S4

      Remove the shift solenoid valve S4.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Solenoid Connector (S4) - Solenoid Body (S4) 20°C (68°F) 11 to 15 Ω

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

      OK
      The solenoid makes an operating sound.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE SHIFT SOLENOID VALVE S4 Click here

    OK

  4. INSPECT SHIFT SOLENOID VALVE SL2


    1. B003VU8C45
      *a Shift Solenoid Valve SL2

      Remove the shift solenoid valve SL2.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 - 2 20°C (68°F) 5.0 to 5.6 Ω

    3. Connect the positive (+) lead with a 21 W bulb to terminal 1 and the negative (-) lead to terminal 2 of the solenoid valve connector, then check the movement of the valve.

      OK
      The solenoid makes an operating sound.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE SHIFT SOLENOID VALVE SL2 Click here

    OK

  5. INSPECT TRANSMISSION VALVE BODY ASSEMBLY


    1. Check the transmission valve body assembly.

      Click here

      OK
      There is no foreign matter on each valve and they operate smoothly.
      Result
      Proceed to
      OK
      NG

    OK

    REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY Click here

    NG

    REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY Click here