AUTOMATIC TRANSAXLE SYSTEM, 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 TCM turning shift solenoid valves SL1, SL2, SL3, SL4 and SL on and off. If an open or short circuit occurs in any of the shift solenoid valves, the TCM controls the remaining normal shift solenoid valves to allow the vehicle to be operated Click here.

DTC Code DTC Detection Condition Trouble Area
P0748 An open or short circuit (output signal duty is 0% or 100%) is detected by the TCM in the shift solenoid valve SL1 circuit while driving and shifting between 4th and 5th 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

  • TCM

MONITOR DESCRIPTION

This DTC indicates an open or short in the shift solenoid valve SL1 circuit. The TCM commands gear shifts by turning the shift solenoid valves on or off. When there is an open or short circuit in any shift solenoid valve circuit, the TCM detects the problem, illuminates the MIL and stores the DTC. The TCM 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 TCM stops sending current to the circuit).

While driving and shifting between 4th and 5th gears, if the TCM detects an open or short in the shift solenoid valve SL1 circuit, the TCM determines there is a malfunction Click here.

WIRING DIAGRAM

A004R6SE01
*1 Shift Solenoid Valve SL1
*2 Transmission Valve Body Assembly
*3 Transmission Wire
*4 Automatic Transaxle Assembly

CAUTION / NOTICE / HINT

Tech Tips

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

TCM gear shift command 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. A004ORKE03
      Text in Illustration
      *1

      Component without TCM connected

      (Transmission Wire)

      Remove the TCM.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      14 (SL1+) - 13 (SL1-) 20°C (68°F) 5.0 to 5.6 Ω
      14 (SL1+) - Body ground Always 10 kΩ or higher
      13 (SL1-) - Body ground Always 10 kΩ or higher
      14 (SL1+) - All other terminals except 13 (SL1-) Always 10 kΩ or higher
      13 (SL1-) - All other terminals except 14 (SL1+) Always 10 kΩ or higher

    OK

    REPLACE TCM Click here

    NG

  2. INSPECT SHIFT SOLENOID VALVE SL1


    1. A004QM7E68
      Text in Illustration
      *1

      Component without harness connected

      (Shift Solenoid Valve SL1)

      Remove 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. 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

    OK

    REPLACE TRANSMISSION WIRE Click here

    NG

    REPLACE SHIFT SOLENOID VALVE SL1 Click here