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 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 mechanical problems with the shift solenoid valve SLU, 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). |
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MONITOR DESCRIPTION
Torque converter assembly lock-up is controlled by the ECM 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 ECM determines the lock-up status of the torque converter assembly by comparing the engine speed (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 assembly.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 illuminate the MIL and store the DTC.
Example:
When one of the following conditions is met, the system determines that there is a malfunction.
- There is a difference in rotation between the input side (engine speed) and output side (input turbine speed) of the torque converter assembly when the ECM commands lock-up ON.
Engine speed is at least 70 rpm more than input turbine speed. - There is no difference in rotation between the input side (engine speed) and output side (input turbine speed) of the torque converter assembly when the ECM commands lock-up OFF.
The difference between engine speed and input turbine speed is less than 35 rpm.
INSPECTION PROCEDURE
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.
Warm up the engine.
Turn the ignition switch off.
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Active Test.
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 Control shift solenoid valve SLU to set automatic transmission to lock-up condition ON or OFF It is possible to check the shift solenoid valve SLU operation.
[Vehicle Condition]- The throttle valve opening angle is less than 35%.
- The vehicle speed is 80 km/h (50 mph) or more.
- HINT:
- This test can be conducted when the vehicle speed is 80 km/h (50 mph) or more.
- Perform this test while driving in the 5th or 6th gear.
- The throttle valve opening angle is less than 35%.
Lightly depress the accelerator pedal and check that the engine speed does not change abruptly.
- HINT:
- When changing the accelerator pedal opening angle while driving, if the engine speed does not change, lock-up is on.
- 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) |
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the DTCs using the GTS.
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.
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A | |
2.INSPECT SHIFT SOLENOID VALVE SLU |
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Remove the shift solenoid valve SLU.
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
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 - Battery positive (+) with a 21 W bulb → Terminal 2
- Battery negative (-) → Terminal 1
Valve moves and makes an operating noise - Battery positive (+) with a 21 W bulb → Terminal 2
*a | Component without harness connected (Shift Solenoid Valve SLU) |
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OK | |
3.INSPECT TRANSMISSION VALVE BODY ASSEMBLY |
Check the transmission valve body assembly (Click here).
- OK:
- There are no foreign objects on any valve.
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OK | |
4.INSPECT TORQUE CONVERTER ASSEMBLY |
Check the torque converter assembly (Click here).
- OK:
- The torque converter assembly operates normally.
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OK | ||
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