AUTOMATIC TRANSMISSION SYSTEM, Diagnostic DTC:P0748

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

DESCRIPTION

Shifting from 1st to 6th is performed in combination with the ON and OFF operation of shift solenoid valves SL1, SL2, S1, S2, S3, S4 and SR, which are controlled by the ECM. If an open or short circuit occurs in the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated safely (Click here).

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P0748

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

The ECM checks for an open or short in the shift solenoid valve SL1 circuit while driving and shifting between 4th and 5th gear (1-trip detection logic).

Output signal duty equals 100%.

  • Open or short in shift solenoid valve SL1 circuit

  • Shift solenoid valve SL1

  • ECM

Comes on

DTC stored
Tip:

SL1 output signal duty is less than 100% under normal conditions.

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 open or short-circuited solenoid.

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

C220887E09

CAUTION / NOTICE / HINT

Tip:

Shift solenoid valve SL1 turns ON/OFF normally when the shift lever is in D:

ECM gear shift command

1st

2nd

3rd

4th

5th

6th

Shift solenoid valve SL1

OFF

OFF

OFF

OFF

ON

ON

PROCEDURE

  1. INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE SL1)

    1. C210154C02

      *a

      Component without harness connected

      (Transmission Wire)

      Disconnect the C24 transmission wire connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      16 (SL1+) - 5 (SL1-)

      20°C (68°F)

      5.0 to 5.6 Ω

      16 (SL1+) - Body ground

      Always

      10 kΩ or higher

      5 (SL1-) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    INSPECT SHIFT SOLENOID VALVE SL1Click here

    OK

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

    1. C214337C07

      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the C30 ECM connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      C30-33 (SL1+) - C30-32 (SL1-)

      20°C (68°F)

      5.0 to 5.6 Ω

      C30-33 (SL1+) - Body ground

      Always

      10 kΩ or higher

      C30-32 (SL1-) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE ECM

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  3. INSPECT SHIFT SOLENOID VALVE SL1

    1. C197715C02

      *a

      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

    Result

    Proceed to

    OK

    NG
    OK

    REPAIR OR REPLACE TRANSMISSION WIRE

    Click here

    NG

    REPLACE SOLENOID VALVE SL1

    Click here