AUTOMATIC TRANSMISSION SYSTEM (for 1TR-FE), Diagnostic DTC:P0748

DTC Code DTC Name
P0748 Pressure Control Solenoid "A" Electrical (Shift Solenoid Valve SL1)

DESCRIPTION

Changing from 1st to 6th is performed by the ECM turning shift solenoid valves SL1, SL2, SL3 and SL4 on and off. If an open or short circuit occurs in any of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated Click here.

DTC No. DTC Detection Condition Trouble Area
P0748 An open or short circuit (output signal duty is 0% or 100%) is detected by the ECM in the shift solenoid valve SL1 circuit while driving and shifting gears (SL1 output signal duty is more than 0% and less than 100% under normal conditions) (1 trip detection logic).
  • Open or short in shift solenoid valve SL1 circuit

  • Shift solenoid valve SL1

  • ECM

MONITOR DESCRIPTION

This DTC indicates an open or short in the shift solenoid valve SL1 circuit. The ECM commands gear shifts by turning the shift solenoid valves on or off. When there is an open or short circuit in any of the shift solenoid valve circuits, the ECM detects the problem and illuminates the MIL and stores the DTC. The ECM also performs the fail-safe function and turns the other normal shift solenoid valves on or off. (In case of an open or short circuit, the ECM stops sending current to the circuit.)

While driving and shifting gears, if the ECM detects an open or short in the shift solenoid valve SL1 circuit, the ECM determines there is a malfunction Click here.

WIRING DIAGRAM

A003AN9E12

INSPECTION PROCEDURE

Note

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

Tech Tips

The following table shows normal operation of the shift solenoid valve SL1 when the shift lever is in D:

ECM commanded gear 1st 2nd 3rd 4th 5th 6th
Shift solenoid valve SL1 ON ON ON ON OFF OFF

PROCEDURE


  1. INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE SL1)


    1. A003HR8E03
      Text in Illustration
      *a

      Component without harness connected

      (Transmission Wire)

      Disconnect the transmission wire connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      25 (SL1+) - 26 (SL1-) 20°C (68°F) 5.0 to 5.6 Ω
      25 (SL1+) - Body ground Always 10 kΩ or higher
      26 (SL1-) - Body ground Always 10 kΩ or higher

    NG
    OK
  2. CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)


    1. A003FZ6E03
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D116-11 (SL1+) - D116-10 (SL1-) 20°C (68°F) 5.0 to 5.6 Ω
      D116-11 (SL1+) - Body ground Always 10 kΩ or higher
      D116-10 (SL1-) - Body ground Always 10 kΩ or higher

    NG
    OK
  3. INSPECT SHIFT SOLENOID VALVE SL1


    1. A003ETNE25
      Text in Illustration
      *1 Shift Solenoid Valve SL1

      Remove shift solenoid valve SL1 Click here.

    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

    NG
    OK