Dtc P0778 Pressure Control Solenoid B Electrical (Shift Solenoid Valve Sl2)


DESCRIPTION

MONITOR DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE SL2)

CHECK WIRE HARNESS (TRANSMISSION WIRE - ECM)

INSPECT SHIFT SOLENOID VALVE SL2

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


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 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 valve to allow the vehicle to be operated safely (Toyota Fortuner RM000000O8L01GX.html).

DTC No.
DTC Detection Condition
Trouble Area
P0778
ECM checks for an open or short in shift solenoid valve SL2 circuit while driving and shifting between 4th and 5th gear (1 trip detection logic)
Output signal duty equal to 100%
HINT:
SL2 output signal duty is less than 100% under normal conditions
  1. Open or short in shift solenoid valve SL2 circuit
  2. Shift solenoid valve SL2
  3. ECM

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/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 the 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 SL2 circuit, the ECM determines that there is a malfunction (Toyota Fortuner RM000000O8L01GX.html).

WIRING DIAGRAM


Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.A750F Automatic Transmission.Automatic Transmission System. Dtc P0778 Pressure Control Solenoid B Electrical (Shift Solenoid Valve Sl2)


INSPECTION PROCEDURE


HINT:
The shift solenoid valve SL2 turns ON/OFF normally when the shift lever is on D:

ECM gear shift command
1st
2nd
3rd
4th
5th
Shift solenoid valve SL2
ON
ON
ON
ON
OFF
1.INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE SL2)


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.A750F Automatic Transmission.Automatic Transmission System. Dtc P0778 Pressure Control Solenoid B Electrical (Shift Solenoid Valve Sl2)

  1. Disconnect the E1 wire connector.

  1. Measure the resistance of the wire connector.

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    11 (SL2+) - 3 (SL2-)
    		20°C (68°F)
    		5.0 to 5.6 Ω
    11 (SL2+) - Body ground
    		20°C (68°F)
    		1 MΩ or higher
    3 (SL2-) - Body ground
    		20°C (68°F)
    		1 MΩ or higher


NG
Go to step 3
OK


2.CHECK WIRE HARNESS (TRANSMISSION WIRE - ECM)


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.A750F Automatic Transmission.Automatic Transmission System. Dtc P0778 Pressure Control Solenoid B Electrical (Shift Solenoid Valve Sl2)

  1. Disconnect the E16 ECM connector.

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

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    E16-17 (SL2+) - E16-16 (SL2-)
    		20°C (68°F)
    		5.0 to 5.6 Ω
    E16-17 (SL2+) - Body ground
    		20°C (68°F)
    		1 MΩ or higher
    E16-16 (SL2-) - Body ground
    		20°C (68°F)
    		1 MΩ or higher


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

REPLACE ECM

3.INSPECT SHIFT SOLENOID VALVE SL2
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.A750F Automatic Transmission.Automatic Transmission System. Dtc P0778 Pressure Control Solenoid B Electrical (Shift Solenoid Valve Sl2)

  1. Remove the shift solenoid valve SL2.

  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 with a 21 W bulb to terminal 2 and the negative (-) lead to terminal 1 of the solenoid valve connector. Then check that the valve moves and makes an operating noise.

    OK:
    Valve moves and makes operating noise.

    HINT:
    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.A750F Automatic Transmission.Automatic Transmission System. Dtc P0778 Pressure Control Solenoid B Electrical (Shift Solenoid Valve Sl2)
    Reference: Inspect using an oscilloscope.
    Check the waveform of the ECM connector.
    OK:
    Refer to illustration.
    Item
    		Content
    Tester Connection
    		E16-17 (SL2+) - E16-16 (SL2-)
    Tool Setting
    		5 V/DIV., 1 msec./DIV.
    Condition
    		Engine idle speed


NG
REPLACE SHIFT SOLENOID VALVE SL2
OK

REPAIR OR REPLACE TRANSMISSION WIRE