СИСТЕМА АВТОМАТИЧЕСКОЙ ТРАНСМИССИИ (для моделей с 3ZR-FE), Diagnostic DTC:P0746

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

DESCRIPTION

The ECM uses signals from the vehicle speed sensor to detect the actual gear position (1st, 2nd, 3rd or 4th 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 transaxle (clutch, brake, gear, etc.).

DTC Code DTC Detection Condition Trouble Area
P0746 The gear required by the ECM does not match the actual gear when driving (2 trip detection logic).
  • Shift solenoid valve SL1 remains open or closed

  • Valve body is blocked

  • Shift solenoid valve SL1

  • Torque converter clutch

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

MONITOR DESCRIPTION

The ECM commands gear shifts by turning the shift solenoid valves ON/OFF. According to the input shaft revolution, intermediate (counter) shaft revolution and output shaft revolution, the ECM detects the actual gear position (1st, 2nd, 3rd or 4th gear). When the gear position commanded by the ECM and the actual gear position are not the same, the ECM illuminates the MIL.

Example:

When either condition (a) or (b) is met, the ECM detects a malfunction.

(a) The ECM commands 1st gear, but the actual gear is 2nd.

(b) The ECM commands 2nd gear, but the actual gear is 1st.

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 / Engine and 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 confirmation of the problem Click here.

      Engine and ECT
      Tester Display Test Part 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

      It is possible to check the operation of the shift solenoid valves.

      [Vehicle Condition]

      The vehicle speed is 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 shift position commanded by the ECM is shown in the Data List / Shift Status display on the tester.

PROCEDURE

  1. CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0746)

    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 / Engine and ECT / DTC.

    5. Read the DTCs using the tester.

      Result
      Result Proceed to
      Only P0746 is output A
      P0746 and other DTCs are output B

      Tech Tips

      If any other codes besides P0746 are output, perform the troubleshooting for those DTCs first.

    B
    A
  2. INSPECT SHIFT SOLENOID VALVE SL1

    1. Remove shift solenoid valve SL1.

      A005V5JE01
    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. 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 (+) with a 21 W bulb → Terminal 1

      • Battery negative (-) → Terminal 2

      Valve moves and makes an operating noise
      Text in Illustration
      *1

      Component without harness connected

      (Shift Solenoid Valve SL1)

    NG
    OK
  3. 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
  4. INSPECT TORQUE CONVERTER CLUTCH ASSEMBLY

    1. Check the torque converter clutch assembly Click here.

      OK
      The torque converter clutch operates normally.
    NG
    OK