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

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DESCRIPTION

Shifting from 1st to 5th is performed in combination with the ON and OFF operation of the shift solenoid valves SL1, SL2, S1, S2 and SR, which is controlled by the ECM. If an open or short circuit occurs in the shift solenoid valves, the ECM controls the remaining normal shift solenoid valve to allow the vehicle to be operated safely (Click here).

DTC No.
DTC Detection Condition
Trouble Area
P0748
ECM checks for an open or short in shift solenoid valve SL1 circuit while driving and shifting between 4th and 5th gear (1 trip detection logic)
Output signal duty equal to 100%

HINT:
SL1 output signal duty is less than 100% under normal condition

  1. Open or short in shift solenoid valve SL1 circuit
  2. Shift solenoid valve SL1
  3. 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/OFF. When there is an open or short circuit in any shift solenoid valve circuit, the ECM detects the problem, illuminates the MIL and stores the DTC. Also, 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.
While driving and shifting between 4th and 5th gears, if the ECM detects an open or short in the shift solenoid valve SL1 circuit, the ECM determines that there is a malfunction (Click here).

WIRING DIAGRAM


A110976E01


INSPECTION PROCEDURE


HINT:
The shift solenoid valve SL1 turns ON/OFF normally when the shift lever is on D:

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

1.INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE SL1)


    G020667E23

  1. Disconnect the E1 wire connector.

  1. Measure the resistance of the wire connector.

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    12 (SL1+) - 4 (SL1-)
    		20°C (68°F)
    		5.0 to 5.6 Ω
    12 (SL1+) - Body ground
    		20°C (68°F)
    		10 kΩ or higher
    4 (SL1-) - Body ground
    		20°C (68°F)
    		10 kΩ or higher



NG
Go to step 3
OK


2.CHECK WIRE HARNESS (TRANSMISSION WIRE - ECM)


    G035616E03

  1. Disconnect the E16 ECM connector.

  1. Measure the resistance of the wire harness side connector.

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    E16-19 (SL1+) - E16-18 (SL1-)
    		20°C (68°F)
    		5.0 to 5.6 Ω
    E16-19 (SL1+) - Body ground
    		20°C (68°F)
    		10 kΩ or higher
    E16-18 (SL1-) - Body ground
    		20°C (68°F)
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

REPLACE ECM 

3.INSPECT SHIFT SOLENOID VALVE SL1
D025466E03

  1. Remove the shift solenoid valve SL1.

  1. Measure the resistance of the solenoid valve.

    Standard resistance:
    5.0 to 5.6 Ωat 20°C (68°F)



  1. Connect the battery's positive (+) lead to the terminal of the solenoid connector, and the negative (-) lead to the solenoid body.

    OK:
    Solenoid makes operating noise.


    HINT:
    A110977E01
    Reference: Inspect using an oscilloscope.
    Check the waveform of the ECM connector.

    Standard voltage:
    Refer to illustration.
    Item
    		Content
    Tester Connection
    		E16-19 (SL1+) - E16-18 (SL1-)
    Tool Setting
    		5 V/DIV., 1 msec./DIV.
    Condition
    		Engine idle speed



NG
REPLACE SHIFT SOLENOID VALVE SL1
OK

REPAIR OR REPLACE TRANSMISSION WIRE