Dtc P0778 Pressure Control Solenoid B Electrical

Drivetrain. Land Cruiser. Urj200, 202 Grj200 Vdj200
Ae80F Automatic Transmission Transaxle. Land Cruiser. Urj200, 202 Grj200 Vdj200

DESCRIPTION

MONITOR DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK HARNESS AND CONNECTOR (SHIFT SOLENOID VALVE SL2 - TCM)

CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - TCM)

INSPECT SHIFT SOLENOID VALVE SL2

DTC P0778 Pressure Control Solenoid "B" Electrical


DESCRIPTION

Based on the ON-OFF combinations of the shift solenoid valve SL1, SL2, SL3, SL4 and SL5, the TCM performs gear shifts from 1st gear to 8th gear.
If a circuit related to a solenoid valve is open or shorted, the TCM uses the fail-safe function to turn other solenoid valves ON or OFF. If all solenoid valves are malfunctioning, only the mechanical fluid pressure circuit will function and some manual operation will be possible. If an open or short has occurred, the TCM cuts power to the malfunctioning solenoid valve.

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

Shift Solenoid Valve Operation:
Gear
1st
2nd
3rd
4th
5th
6th
7th
8th
Shift Solenoid Valve SL2
ON
ON
ON
ON
OFF
OFF
OFF
OFF

DTC No.
DTC Detection Condition
  1. Diagnosis Condition
  2. Malfunction Status
  3. Malfunction Time
  4. Other
Trouble Area
P0778
  1. Driving so that gear changes occur
  2. Shift solenoid valve SL2 circuit is open or shorted
  3. 2 seconds
  4. 1-trip detection logic
  1. Shift solenoid valve SL2
  2. Transmission wire
  3. Harness or connector
  4. TCM

MONITOR DESCRIPTION

This DTC indicates an open or short in the shift solenoid valve SL2 circuit. The TCM 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 TCM detects the problem, illuminates the MIL and stores a DTC. The TCM 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 TCM stops sending current to the open or short circuited solenoid.

WIRING DIAGRAM


Land Cruiser. Urj200, 202 Grj200 Vdj200.Ae80F Automatic Transmission Transaxle.Automatic Transmission System. Dtc P0778 Pressure Control Solenoid B Electrical


INSPECTION PROCEDURE

NOTICE:
Perform registration and/or initialization when parts related to the automatic transmission are replaced (Click here).
HINT:
After performing repair, clear the DTCs and perform the following procedure to check that DTCs are not output.
  1. Perform the D Position Shift Test in Road Test (Click here).
  2. Check for DTCs again (Click here).
1.CHECK HARNESS AND CONNECTOR (SHIFT SOLENOID VALVE SL2 - TCM)


    Land Cruiser. Urj200, 202 Grj200 Vdj200.Ae80F Automatic Transmission Transaxle.Automatic Transmission System. Dtc P0778 Pressure Control Solenoid B Electrical

  1. Disconnect the TCM connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A80-3 (SL2+) - A80-2 (SL2-)
    		20°C (68°F)
    		5.0 to 5.6 Ω
    A80-3 (SL2+) or A80-2 (SL2-) - Body ground
    		Always
    		10 kΩ or higher
    Text in Illustration
    *a
    		Rear view of wire harness connector
    (to TCM)


NG
Go to step 2
OK

REPLACE TCM (Click here)

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

  1. Disconnect the C171 transmission wire connector.

  1. Disconnect the A80 TCM connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    C171-15 (SL2+) - A80-3 (SL2+)
    		Always
    		Below 1 Ω
    C171-16 (SL2-) - A80-2 (SL2-)
    		Always
    		Below 1 Ω
    C171-15 (SL2+) or A80-3 (SL2+) - Body ground
    		Always
    		10 kΩ or higher
    C171-16 (SL2-) or A80-2 (SL2-) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.INSPECT SHIFT SOLENOID VALVE SL2


    Land Cruiser. Urj200, 202 Grj200 Vdj200.Ae80F Automatic Transmission Transaxle.Automatic Transmission System. Dtc P0778 Pressure Control Solenoid B Electrical

  1. Remove the shift solenoid valve SL2 (Click here).

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    Terminal 1 of the shift solenoid valve SL2 - Terminal 2
    		20°C (68°F)
    		5.0 to 5.6 Ω

  1. 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
    1. Battery positive (+) with a 21 W bulb → Terminal 2
    2. Battery negative (-) → Terminal 1
    		Valve moves and makes an operating noise
Text in Illustration
*1
Shift Solenoid Valves SL2


NG
REPLACE SHIFT SOLENOID VALVE SL2 (Click here)
OK

REPAIR OR REPLACE TRANSMISSION WIRE (Click here)