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 ECM 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 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

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


  • Output signal duty equals 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

  • Wiring harness connector

  • 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 shift solenoid valve circuit, 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 between 4th and 5th 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.

MONITOR STRATEGY

Related DTCs P0748: Shift solenoid valve SL1/Range check
Required sensors/Components Shift solenoid valve SL1
Frequency of operation Continuous
Duration 1 sec.
MIL operation Immediate
Sequence of operation None

TYPICAL ENABLING CONDITIONS

All
The monitor will run whenever the following DTCs are not present None
Ignition switch ON
Starter OFF
Condition (A)
Battery voltage 12 V or more
Condition (B)
Battery voltage 10 V or more and less than 12 V
Target current Less than 0.75 A
Condition (C)
Battery voltage 8 V or more
Target current 0.6 A or more

TYPICAL MALFUNCTION THRESHOLDS

When one of the following conditions is met: Condition (A), (B) or (C)

Condition (A) and (B)
Output duty cycle 100% or more
Condition (C)
Output duty cycle 0% or less

COMPONENT OPERATING RANGE

Output duty cycle More than 0% and less than 100%

WIRING DIAGRAM

A01HPJSE05

INSPECTION PROCEDURE

Note

Perform the universal trip to clear permanent DTCs 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. CHECK HARNESS AND CONNECTOR (SHIFT SOLENOID VALVE SL1 CIRCUIT)


    1. A01HP4DE06
      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
      E26-5 (SL1+) - E26-4 (SL1-) 20°C (68°F) 5.0 to 5.6 Ω
      E26-5 (SL1+) - Body ground and other terminals Always 10 kΩ or higher
      E26-4 (SL1-) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Result Proceed to
      OK A
      NG B

    B

    CHECK HARNESS AND CONNECTOR (ECM - WIRING HARNESS CONNECTOR) Click here

    A

    REPLACE ECM Click here

  2. CHECK HARNESS AND CONNECTOR (ECM - WIRING HARNESS CONNECTOR)


    1. Disconnect the connector from the wiring harness connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E26-5 (SL1+) - E8-17 (SL1+) Always Below 1 Ω
      E26-4 (SL1-) - E8-16 (SL1-) Always Below 1 Ω
      E26-5 (SL1+) or E8-17 (SL1+) - Body ground and other terminals Always 10 kΩ or higher
      E26-4 (SL1-) or E8-16 (SL1-) - Body ground and other terminals Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT TRANSMISSION WIRE (SL1)


    1. A01HQ89E56
      Text in Illustration
      *a

      Component without harness connected

      (Transmission Wire)

      Remove the wiring harness connector from the transaxle.

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

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

    NG

    INSPECT SHIFT SOLENOID VALVE SL1 Click here

    OK

    REPLACE WIRING HARNESS CONNECTOR Click here

  4. INSPECT SHIFT SOLENOID VALVE SL1


    1. A01HMPNE01
      Text in Illustration
      *1 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. Connect a battery positive (+) lead with a 21 W bulb to terminal 2 and a negative (-) lead to terminal 1 of the solenoid valve connector. Then check that the valve moves and makes an operating sound.

      OK
      Valve moves and makes an operating sound.

    NG

    REPLACE SHIFT SOLENOID VALVE SL1 Click here

    OK

    REPLACE TRANSMISSION WIRE Click here