Lexus IS250 IS220d GSE20 ALE20 - A960E AUTOMATIC TRANSMISSION
CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P2757)
INSPECT SHIFT SOLENOID VALVE SLU
INSPECT TRANSMISSION VALVE BODY ASSEMBLY
INSPECT TORQUE CONVERTER CLUTCH 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, turbine (input) speed sensor, output speed sensor and crankshaft position sensor to monitor the engagement condition of the lock-up clutch.
Then the ECM compares the engagement condition of the lock-up clutch with the lock-up schedule in the ECM memory to detect a mechanical problems of the shift solenoid valve SLU, valve body and torque converter clutch.
| DTC No. | 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) |
Shift solenoid valve SLU remains open or closed Valve body is blocked Torque converter clutch Automatic transmission (clutch, brake or gear, etc.) Line pressure is too low |
MONITOR DESCRIPTION
Torque converter lock-up is controlled by the ECM based on the turbine (input) speed sensor NT, output speed sensor SP2, engine rpm, engine load, engine temperature, vehicle speed, transmission temperature, and gear selection. The ECM determines the lock-up status of the torque converter by comparing the engine rpm (NE) to the input turbine rpm (NT). The ECM calculates the actual transmission gear by comparing input turbine rpm (NT) to output shaft rpm (SP2). When conditions are appropriate, the ECM requests "lock-up" by applying control voltage to the shift solenoid SLU. When the SLU is turned on, it applies pressure to the lock-up relay valve and locks the torque converter clutch.
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 the shift solenoid valve SLU or lock-up system performance.
The ECM will turn on the MIL and store the DTC.
Example:
When any of the following is met, the system judges it as a malfunction.
(Engine speed is at least 70 rpm greater than input turbine speed.)
(The difference between engine speed and input turbine speed is less than 35 rpm.)
INSPECTION PROCEDURE
| ACTIVE TEST |
- HINT:
- Performing the intelligent tester Active Test allows relay, Vacuum Switching Valve (VSV), actuator and other items to be operated without removing any parts. Performing the Active Test early in troubleshooting is one way to shorten labor time.
- The Data List can be displayed during the Active Test.
Warm up the engine.
Turn the engine switch off.
Connect the intelligent tester together to the DLC3.
Turn the engine switch on (IG) position.
Turn on the tester.
Select the item "Enter / Powertrain / ECT / Active Test".
Follow the instructions on the tester and read the Active Test.
| Item | Test Details | Diagnostic Note |
| Control the Lock Up | [Test Details] Control the shift solenoid SLU to set the automatic transmission to the lock-up condition. [Vehicle Condition] Throttle valve opening angle: Less than 35 % Vehicle Speed: 60 km/h (37 mph) or more |
Possible to check the SLU operation. |
- HINT:
Lightly depress the accelerator pedal and check that the engine speed does not change abruptly.
- HINT:
| 1.CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P2757) |
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG) position.
Turn on the tester
Select the item "Powertrain / ECT / DTC / Current or Pending".
Read the DTCs using the intelligent tester.
- Result:
Display (DTC output) Proceed to Only "P2757" is output A "P2757" and other DTCs B
- HINT:
- If any other codes besides "P2757" are output, perform troubleshooting for those DTCs first.
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| A | |
| 2.INSPECT SHIFT SOLENOID VALVE SLU |
Remove the shift solenoid valve SLU.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection Specified Condition
20°C (68°F)1 - 2 5.0 to 5.6 Ω
Connect the positive (+) lead with a 21 W bulb to terminal 2 and the negative (-) lead to terminal 1 of the solenoid valve connector, then check the movement of the valve.
- OK:
- The solenoid makes an operating sound.
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| OK | |
| 3.INSPECT TRANSMISSION VALVE BODY ASSEMBLY |
- OK:
- There are no foreign objects on each valve.
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| OK | |
| 4.INSPECT TORQUE CONVERTER CLUTCH ASSEMBLY |
Check the torque converter clutch assembly .
- OK:
- The torque converter clutch operates normally.
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| OK | ||
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