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

Drivetrain. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25
A750F Automatic Transmission Transaxle. Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25

DESCRIPTION

MONITOR DESCRIPTION

INSPECTION PROCEDURE

CHECK DTC 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)


DESCRIPTION

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

Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.A750F Automatic Transmission Transaxle.Automatic Transmission System (For 1Gr-Fe). Dtc P2757 Torque Converter Clutch Pressure Control Solenoid Performance (Shift Solenoid Valve Slu)

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

DTC Code
DTC Detection Condition
Trouble Area
P2757
Lock-up does not occur when driving in the lock-up range (normal driving at 80 km/h (50 mph)), or lock-up remains ON in the lock-up OFF range (2-trip detection logic).
  1. Shift solenoid valve SLU remains open or closed
  2. Valve body is blocked
  3. Torque converter assembly
  4. Automatic transmission (clutch, brake, gear, etc.)
  5. Line pressure is too low

MONITOR DESCRIPTION

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

INSPECTION PROCEDURE


ACTIVE TEST
HINT:
Using the intelligent tester 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 ignition switch off.

  3. Connect the intelligent tester to the DLC3.

  4. Turn the ignition switch to ON.

  5. Turn the intelligent tester on.

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

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

    ECT
    Tester Display
    		Test Part
    		Control Range
    		Diagnostic Note
    Activate the Lock Up
    		Control shift solenoid valve SLU to set automatic transmission to lock-up
    		ON or OFF
    		Possible to check shift solenoid valve SLU operation.
    [Vehicle Condition]
    1. Throttle valve opening angle: Less than 35%
    2. Vehicle speed: 60 km/h (37 mph) or more
    HINT:
    1. This test can be conducted when the vehicle speed is 60 km/h (37 mph) or more.
    2. This test can be conducted with the 5th gear.


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


    Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.A750F Automatic Transmission Transaxle.Automatic Transmission System (For 1Gr-Fe). Dtc P2757 Torque Converter Clutch Pressure Control Solenoid Performance (Shift Solenoid Valve Slu)

    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 automatically.)
1.CHECK DTC OUTPUT (IN ADDITION TO DTC P2757)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the intelligent tester on.

  1. Enter the following menus: Powertrain / ECT / DTC.

  1. Read the DTCs using the tester.

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


B
GO TO DTC CHART (HILUX_TGN26 RM0000030G907BX.html)
A


2.INSPECT SHIFT SOLENOID VALVE SLU


    Hilux. Tgn26, 36 Kun25, 26, 35, 36 Ggn25.A750F 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.

  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 2
    2. Battery negative (-) → Terminal 1
    		Valve moves and makes an operating noise
Text in Illustration
*a
Component without harness connected
(Shift Solenoid Valve SLU)


NG
REPLACE SHIFT SOLENOID VALVE SLU (HILUX_TGN26 RM0000013FG02KX_01_0003.html)
OK


3.INSPECT TRANSMISSION VALVE BODY ASSEMBLY

  1. Check the transmission valve body assembly (HILUX_TGN26 RM0000013FG02KX.html).

    OK:
    There are no foreign objects on any valve.


NG
REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY (HILUX_TGN26 RM0000013CM049X.html)
OK


4.INSPECT TORQUE CONVERTER ASSEMBLY

  1. Check the torque converter assembly (HILUX_TGN26 RM0000013F203XX.html).

    OK:
    The torque converter assembly operates normally.


NG
REPLACE TORQUE CONVERTER ASSEMBLY (HILUX_TGN26 RM0000013F6019X.html)
OK

REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY (HILUX_TGN26 RM0000013F6019X.html)