AUTOMATIC TRANSAXLE SYSTEM, Diagnostic DTC:P0748

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

DESCRIPTION

Shifting from 1st to 5th is performed in combination with "ON" and "OFF" operation of the shift solenoid valves SL1, SL2, SL3, S4 and SR which are controlled by the ECM. If an open or short circuit occurs in either of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated smoothly (Fail safe function).

DTC No. DTC Detection Condition Trouble Area
P0748

The ECM checks for an open or short in the shift solenoid valve SL1 circuit while driving and shift gears.

(1-trip detection logic)


  • Output signal duty equals to 100 %.

    (NOTE: SL1 output signal duty is less than 100 % under normal condition.)

  • Open or short in shift solenoid valve SL1 circuit

  • Shift solenoid valve SL1

  • ECM

MONITOR DESCRIPTION

The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". When there is an open or short circuit in any shift solenoid valve circuit, the ECM detects the problem and illuminates the MIL and stores the DTC. And the ECM performs the fail-safe function and turns the other normal shift solenoid valves "ON/OFF" (In case of an open or short circuit, the ECM stops sending current to the circuit.) Click here.

WIRING DIAGRAM

A017FXEE63

INSPECTION PROCEDURE

PROCEDURE


  1. INSPECT TRANSMISSION WIRE (SL1)


    1. A017EZRE51

      Disconnect the transmission wire connector from the transaxle.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      6 (SL1+) - 13 (SL1-) 20°C (68°F) 5.0 to 5.6 Ω

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

      Standard resistance (Check for short)
      Tester Connection Condition Specified Condition
      6 (SL1+) - Body ground Always 10 kΩ or higher
      13 (SL1-) - Body ground Always ↑

    NG

    INSPECT SHIFT SOLENOID VALVE (SL1) Click here

    OK

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


    1. A017CYDE13

      Connect the transmission wire connector to the transaxle.

    2. Disconnect the ECM connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      B2-19 (SL1+) - B2-18 (SL1-) 20°C (68°F) 5.0 to 5.6 Ω

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

      Standard resistance (Check for short)
      Tester Connection Condition Specified Condition
      B2-19 (SL1+) - Body ground Always 10 kΩ or higher
      B2-18 (SL1-) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM (for 2GR-FE) Click here

  3. INSPECT SHIFT SOLENOID VALVE (SL1)


    1. A017EGEE88

      Remove the shift solenoid valve SL1.

    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 2 and the negative (-) lead to terminal 1 of the solenoid valve connector, then check the movement of the valve.

      OK
      The solenoid makes an operating sound.

    NG

    REPLACE SHIFT SOLENOID VALVE (SL1) Click here

    OK

    REPAIR OR REPLACE TRANSMISSION WIRE Click here