Dtc P2757 Torque Converter Clutch Pressure Control Solenoid Performance (Shift Solenoid Valve Slu)


SYSTEM DESCRIPTION

MONITOR DESCRIPTION

INSPECTION PROCEDURE

CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P2757)

INSPECT SHIFT SOLENOID VALVE SLU

INSPECT TRANSMISSION VALVE BODY ASSEMBLY

INSPECT TORQUE CONVERTER ASSEMBLY

DTC P2757 Torque Converter Clutch Pressure Control Solenoid Performance (Shift Solenoid Valve SLU)


SYSTEM DESCRIPTION

The ECM uses the signals from the throttle position sensor, air-flow meter, input turbine speed sensor, output shaft speed sensor and crankshaft position sensor to monitor the engagement condition of the lock-up clutch.

Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Ac60F Automatic Transmission Transaxle.Automatic Transmission System (For 1Gr-Fe). Dtc P2757 Torque Converter Clutch Pressure Control Solenoid Performance (Shift Solenoid Valve Slu)

The ECM compares the engagement condition of the lock-up clutch with the lock-up schedule in the ECM memory to detect shift solenoid valve SLU, transmission valve body assembly and torque converter assembly mechanical problems.

DTC No.
DTC Detection Condition
Trouble Area
P2757
Both conditions are met (2 trip detection logic):
  1. Lock-up does not occur when requested.
  2. Lock-up occurs when shift solenoid valve SLU is requested to turn on in the lock-up range.
  1. Shift solenoid valve SLU remains open or closed
  2. Transmission valve body assembly is blocked
  3. Torque converter assembly
  4. Automatic transmission assembly (clutch, brake or gear, etc.)
  5. Line pressure is too low

MONITOR DESCRIPTION

Torque converter lock-up is controlled by the ECM based on the transmission revolution sensor (NT), transmission revolution sensor (SP2), engine speed, engine load, engine temperature, vehicle speed, transmission fluid temperature and gear selection. The ECM determines the lock-up status of the torque converter by comparing the engine speed (NE) to the input turbine speed (NT). The ECM calculates the actual transmission gear by comparing the input turbine speed (NT) to the output shaft speed (SP2). When conditions are appropriate, the ECM requests "lock-up" by applying control voltage to shift solenoid valve SLU. When shift solenoid valve SLU is turned on, it applies pressure to the lock-up relay valve and locks the torque converter.
If the ECM detects no lock-up after lock-up has been requested or if it detects lock-up when it is not requested, the ECM interprets this as a fault in shift solenoid valve SLU or lock-up system performance.
The ECM will illuminate the MIL and store the DTC.
HINT:
Example:
When any of the following is met, the system judges it as a malfunction.
  1. There is a difference in rotation speed between the input side (engine speed) and output side (input turbine speed) of the torque converter when the ECM commands lock-up.
    (Engine speed is at least 70 rpm more than the input turbine speed.)
  2. There is no difference in rotation speed between the input side (engine speed) and output side (input turbine speed) of the torque converter when the ECM commands lock-up off.
    (The difference between engine speed and input turbine speed is less than 35 rpm.)

INSPECTION PROCEDURE

NOTICE:
Perform registration and/or initialization when parts related to the automatic transmission are replaced (LandCruiser RM000000O7H0HRX.html).
HINT:
After the repair, clear the DTCs and perform the following procedure to check that DTCs are not output.
  1. Perform the Lock-up Function in Road Test (LandCruiser RM000000W790SFX.html).*1
  2. Turn the engine switch off.
  3. Perform step (*1) again.
  4. Check for DTCs again (LandCruiser RM000000W7711JX.html).

ACTIVE TEST
HINT:
Using the GTS to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.

  1. Warm up the engine.

  2. Turn the engine switch off.

  3. Connect the GTS to the DLC3.

  4. Turn the engine switch on (IG).

  5. Turn the GTS on.

  6. Enter the following menus: Powertrain / Engine and ECT / Active Test.

  7. According to the display on the GTS, perform the Active Test.

    Engine and ECT
    Tester Display
    		Test Part
    		Control Range
    		Diagnostic Note
    Activate the Lock Up
    		Controls the shift solenoid valves SLU and SL to set the automatic transmission to the lock-up condition.
    		ON/OFF
    		Can be used to check shift solenoid valves SLU and SL operation.
    [Vehicle Condition]
    1. Throttle valve opening angle: Less than 10%
    2. Vehicle speed: 80 km/h (50 mph) or more
    HINT:
    1. This test can be conducted when the vehicle speed is 80 km/h (50 mph) or more.


  8. Lightly depress the accelerator pedal and check that the engine speed does not change abruptly.

    HINT:
    1. When changing the accelerator pedal opening angle while driving, if the engine speed does not change, lock-up is on.
    2. Slowly release the accelerator pedal in order to decelerate, but do not fully release the pedal. (Fully releasing the pedal will close the throttle valve and lock-up may be turned off.)

    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Ac60F Automatic Transmission Transaxle.Automatic Transmission System (For 1Gr-Fe). Dtc P2757 Torque Converter Clutch Pressure Control Solenoid Performance (Shift Solenoid Valve Slu)

1.CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P2757)

  1. Connect the GTS to the DLC3.

  1. Turn the engine switch on (IG).

  1. Turn the GTS on.

  1. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

  1. Read the DTCs using the GTS.

    Result
    Result
    		Proceed to
    Only DTC P2757 is output
    		A
    P2757 and other DTCs are output
    		B
    HINT:
    If any DTCs other than P2757 are output, perform troubleshooting for those DTCs first.


B
GO TO DTC CHART (LandCruiser RM000000W710QCX.html)
A


2.INSPECT SHIFT SOLENOID VALVE SLU


    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Ac60F Automatic Transmission Transaxle.Automatic Transmission System (For 1Gr-Fe). Dtc P2757 Torque Converter Clutch Pressure Control Solenoid Performance (Shift Solenoid Valve Slu)

  1. Remove shift solenoid valve SLU (LandCruiser RM000000O9L07IX.html).

  1. 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

  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 1
    2. Battery negative (-) → Terminal 2
    		Valve moves and makes an operating noise
Text in Illustration
*1
Shift Solenoid Valve SLU


NG
REPLACE SHIFT SOLENOID VALVE SLU (LandCruiser RM000000O9L07IX.html)
OK


3.INSPECT TRANSMISSION VALVE BODY ASSEMBLY

  1. Check the transmission valve body assembly (LandCruiser RM000000O9L07IX.html).

    OK:
    There is no foreign matter on each valve and they operate smoothly.


NG
REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY (LandCruiser RM000000O9K022X.html)
OK


4.INSPECT TORQUE CONVERTER ASSEMBLY

  1. Check the torque converter assembly (LandCruiser RM000000OA102PX.html).

    OK:
    The torque converter assembly operates normally.


NG
REPLACE TORQUE CONVERTER ASSEMBLY (LandCruiser RM0000018ZD05KX.html)
OK

REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY (LandCruiser RM0000018ZD05KX.html)