AUTOMATIC TRANSMISSION SYSTEM, Diagnostic DTC:P0746

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

DESCRIPTION

The TCM detects the gear position based on signals from the speed sensors (SP2 and NT).

Based on the detected gear position and oil pressure switch output, the TCM detects related mechanical problems in the shift solenoid valves, valve body and automatic transmission.

Tech Tips

Gear shift position when a problem occurs in shift solenoid valve SL1:

TCM gear shift command 1st 2nd 3rd 4th 5th 6th 7th 8th
Actual gear position under SL1 stuck ON malfunction*1 1st 2nd 3rd 4th 5th 6th 7th 8th
Actual gear position under SL1 stuck OFF malfunction*2 N*3 N*3 N*3 N*3 N*3 6th 7th 8th

  • *1: When the vehicle is running with the transmission in a gear less than 6th

  • *2: When the vehicle is running with the transmission in 6th gear or higher

  • *3: Neutral

DTC Code

DTC Detection Condition


  1. Diagnosis Condition

  2. Malfunction Status

  3. Malfunction Time

  4. Other

 Trouble Area
P0746

  1. ECT is 40°C (104°F) or higher, ATF temperature is -10°C (14°F) or higher, and the vehicle is driven with the shift lever in D (no malfunctions are detected in shift solenoid valve SL1, 2, 3, 4 and 5, SR, speed sensors (NT, NC3, SP2), oil pressure switch, engine coolant temperature sensor, oil temperature sensor, knock control sensor, electronic throttle, or CAN2)

  2. When a gear shift to 6th, 7th, or 8th is requested by the TCM, the oil pressure switch is on

  3. Malfunction status is detected 2 times per trip

  4. 2 trip detection logic

  • Shift solenoid valve SL1

  • Shift solenoid valve SLT

  • Oil pressure switch

  • Valve body assembly

  • Torque converter clutch assembly

  • Automatic transmission assembly
P0746

  1. ECT is 40°C (104°F) or higher, ATF temperature is -10°C (14°F) or higher, and the vehicle is driven with the shift lever in D (no malfunctions are detected in shift solenoid valve SL1, 2, 3, 4 and 5, SR, speed sensors (NT, NC3, SP2), oil pressure switch, engine coolant temperature sensor, oil temperature sensor, knock control sensor, electronic throttle, or CAN2)

  2. When gear shifts to 1st to 5th are requested by the TCM, the engine overruns (neutral status)

  3. Malfunction status continues for 0.5 sec. or more

  4. 2 trip detection logic

  • Shift solenoid valve SL1

  • Shift solenoid valve SLT

  • Oil pressure switch

  • Valve body assembly

  • Torque converter clutch assembly

  • Automatic transmission assembly

MONITOR DESCRIPTION

The TCM commands gear shifts by turning the shift solenoid valves on or off. According to the input shaft speed, intermediate (counter) shaft speed and output shaft speed, the TCM detects the actual gear position (1st, 2nd, 3rd, 4th, 5th, 6th, 7th or 8th gear position). When the gear position commanded by the TCM and the actual gear position are not the same, the TCM illuminates the MIL.

PROCEDURE


  1. CHECK DTC OUTPUT (IN ADDITION TO DTC P0746, P0873 AND P2714)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the intelligent tester on.

    4. Enter the following menus: Powertrain / ECT / DTC.

    5. Read the DTCs using the intelligent tester.

      Result
      Display (DTC output) Proceed to
      Only P0746 and P2714 are output A
      Only P0746 and P0873 are output B
      P0746, P0873, P2714, and other DTCs are output C

      Tech Tips

      If any other codes besides P0746, P0873 and P2714 are output, perform troubleshooting for those DTCs first.


    B

    GO TO DTC P0873 FLOWCHART Click here

    C

    GO TO DTC CHART Click here

    A

  2. CLEAR DTC AND PERFORM RUNNING TEST


    1. Clear the DTCs Click here.

      Tech Tips

      Write down the currently output DTCs before clearing them.

    2. Start the engine, drive at a low speed and perform the inspection.

      Result
      Test Condition Proceed to

      Vehicle cannot be driven

      (vehicle changes to neutral)

      		 A

      Vehicle can be driven

      (vehicle creep occurs)

      		 B

    B

    INSPECT SHIFT SOLENOID VALVE SLT Click here

    A

  3. INSPECT SHIFT SOLENOID VALVE SL1


    1. Remove shift solenoid valve SL1 Click here.

      A0019VFE02
      *a Component without harness connected: (Shift Solenoid Valve SL1)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Terminal 1 of shift solenoid valve SL1 - Terminal 2 20°C (68°F) 5.0 to 5.6 Ω

    3. Connect the battery's positive (+) lead with a 21 W bulb to terminal 2 and the negative (-) lead to terminal 1 of the solenoid valve connector. Then check that the valve moves and makes an operating noise.

      OK
      Valve moves and makes operating noise.

    NG

    REPLACE SHIFT SOLENOID VALVE SL1 Click here

    OK

    INSPECT TRANSMISSION VALVE BODY ASSEMBLY Click here

  4. INSPECT SHIFT SOLENOID VALVE SLT


    1. Remove shift solenoid valve SLT Click here.

      A0019VFE03
      *a Component without harness connected: (Shift Solenoid Valve SLT)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Terminal 1 of shift solenoid valve SLT - Terminal 2 20°C (68°F) 5.0 to 5.6 Ω

    3. Connect the battery's positive (+) lead with a 21 W bulb to terminal 2 and the negative (-) lead to terminal 1 of the solenoid valve connector. Then check that the valve moves and makes an operating noise.

      OK
      Valve moves and makes operating noise.

    NG

    REPLACE SHIFT SOLENOID VALVE SLT 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.

    NG

    REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY Click here

    OK

  6. INSPECT TORQUE CONVERTER CLUTCH ASSEMBLY


    1. Check the torque converter clutch assembly Click here.

      OK
      The torque converter clutch operates normally.

    OK

    REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY Click here

    NG

    REPLACE TORQUE CONVERTER CLUTCH ASSEMBLY Click here