AUTOMATIC TRANSAXLE SYSTEM, Diagnostic DTC:P0778

DTC Code DTC Name
P0778 Pressure Control Solenoid "B" Electrical (Shift Solenoid Valve SL2)

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.

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DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P0778 Pressure Control Solenoid "B" Electrical (Shift Solenoid Valve SL2) An open or short circuit (output signal duty is 0% or 100%) is detected by the ECM in the shift solenoid valve SL2 circuit while driving and shifting gears (SL2 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 SL2 circuit

  • Shift solenoid valve SL2

  • Wiring harness connector

  • ECM

 Comes on DTC stored

MONITOR DESCRIPTION

This DTC indicates an open or short in the shift solenoid valve SL2 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 of the shift solenoid valve circuits, the ECM detects the problem, illuminates the MIL and stores a 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 gears, if the ECM detects an open or short in the shift solenoid valve SL2 circuit, the ECM determines there is a malfunction.

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WIRING DIAGRAM

A002BLLE31
*1 Shift Solenoid Valve SL2
*2 Automatic Transaxle
*3 Wiring Harness Connector

CAUTION / NOTICE / HINT

Tech Tips

The following table shows normal operation of the shift solenoid valve SL2 when the shift lever is in D:

ECM commanded gear 1st 2nd 3rd 4th 5th 6th
Shift solenoid valve SL2 OFF OFF OFF ON ON ON

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (SHIFT SOLENOID VALVE SL2 CIRCUIT)


    1. A0027TIC07
      *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
      C1-13 (SL2+) - C1-12 (SL2-) 20°C (68°F) 5.0 to 5.6 Ω
      C1-13 (SL2+) - Body ground and other terminals Always 10 kΩ or higher
      C1-12 (SL2-) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

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


    1. Disconnect the harness 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
      C1-13 (SL2+) - C2-9 (SL2+) Always Below 1 Ω
      C1-12 (SL2-) - C2-8 (SL2-) Always Below 1 Ω
      C1-13 (SL2+) or C2-9 (SL2+) - Body ground and other terminals Always 10 kΩ or higher
      C1-12 (SL2-) or C2-8 (SL2-) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT TRANSMISSION WIRE (SL2)


    1. A002C2RC04
      *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-9 (SL2+) - A-8 (SL2-) 20°C (68°F) 5.0 to 5.6 Ω
      A-9 (SL2+) - Body ground and other terminals Always 10 kΩ or higher
      A-8 (SL2-) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE WIRING HARNESS CONNECTOR When Not Using the Engine Support Bridge: Click here
    REPLACE WIRING HARNESS CONNECTOR When Using the Engine Support Bridge: Click here

    NG

  4. INSPECT SHIFT SOLENOID VALVE SL2


    1. A0029G2C02
      *1 Shift Solenoid Valve SL2

      Remove shift solenoid valve SL2.

    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.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE TRANSMISSION WIRE Click here

    NG

    REPLACE SHIFT SOLENOID VALVE SL2 When Not Using the Engine Support Bridge: Click here
    REPLACE SHIFT SOLENOID VALVE SL2 When Using the Engine Support Bridge: Click here