AUTOMATIC TRANSMISSION SYSTEM, Diagnostic DTC:P0746 and P0771

DTC Code DTC Name
P0746 Pressure Control Solenoid "A" Performance (Shift Solenoid Valve SL1)
P0771 Shift Solenoid "E" Performance (Shift Solenoid Valve SR)

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

P0746

Pressure Control Solenoid "A" Performance (Shift Solenoid Valve SL1)

The gear required by the ECM does not match the actual gear when driving (2-trip detection logic).

  • Shift solenoid valve SL1 remains closed

  • Shift solenoid valve SR remains open or closed

  • Valve body is blocked

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

Comes on

DTC stored

P0771

Shift Solenoid "E" Performance (Shift Solenoid Valve SR)

The gear required by the ECM does not match the actual gear when driving (2-trip detection logic).

  • Shift solenoid valve SR remains open or closed

  • Shift solenoid valve SL1 remains closed

  • Valve body is blocked

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

Comes on

DTC stored

MONITOR DESCRIPTION

These DTCs indicate a stuck ON malfunction or stuck OFF malfunction of the shift solenoid valves SR and SL1.

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

    Tip:

    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.

      Tip:

      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 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.
      Tip:

      • 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 valves SL1 and SR turn ON/OFF normally when the shift lever is in D.

        ECM gear shift command

        1st

        2nd

        3rd

        4th

        5th

        Shift solenoid valve SL1

        OFF

        OFF

        OFF

        OFF

        ON

        Shift solenoid valve SR

        OFF

        OFF

        OFF

        OFF

        ON

PROCEDURE

  1. CHECK DTC OUTPUT (IN ADDITION TO DTCS P0746 AND P0771)

    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 P0746 and P0771 are output

      • Only P0771 is output

      A

      P0746, P0771 and other DTCs are output

      B
      Tip:

      If any other codes besides P0746 and P0771 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.

    Tip:

    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. C214323N04

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

    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

      Tip:

      • 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.
      Tip:

      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.

    09992-00095

    09992-00231

    09992-00271

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE SHIFT SOLENOID VALVE SLT

    Click here

    OK

  3. INSPECT SHIFT SOLENOID VALVE SL1

    1. Remove shift solenoid valve SL1.

    2. C197715C11

      *a

      Component without harness connected

      (Shift Solenoid Valve SL1)

      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. Apply 12 V battery voltage to the shift solenoid valve and check that the valve moves and makes an operating noise.

      Table 1. OK

      Measurement Condition

      Specified Condition

      • Battery positive (+) with a 21 W bulb → Terminal 1

      • Battery negative (-) → Terminal 2

      Valve moves and makes operating noise

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE SHIFT SOLENOID VALVE SL1

    Click here

    OK

  4. INSPECT SHIFT SOLENOID VALVE SR

    1. Remove shift solenoid valve SR.

    2. C214329C05

      *a

      Component without harness connected

      (Shift Solenoid Valve SR)

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      Shift solenoid valve SR connector terminal - Shift solenoid valve SR 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.

      Table 2. OK

      Measurement Condition

      Specified Condition

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

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

      Valve moves and makes operating noise

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE SHIFT SOLENOID VALVE SR

    Click here

    OK

  5. 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