P2757

DTC P2757 TORQUE CONVERTER CLUTCH PRESSURE CONTROL SOLENOID PERFORMANCE (SHIFT SOLENOID VALVE SLU)

SYSTEM DESCRIPTION

DTC Detection Condition:

The ECM uses the signals from the throttle position sensor, Airflow 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.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions (Part 1):

Typical Enabling Conditions (Part 2):

Typical Malfunction Thresholds:

Component Operating Range:

Torque converter lock-up is controlled by the ECM based on 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 shift solenoid SLU. When the SLU is turned on, solenoid SLU 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.

a. There is a difference in rotation between before and after torque converters even when the ECM commands lock-up.
(Engine speed is at least 75 rpm greater than input turbine speed.)
b. There is no difference in rotation between before and after torque converters even when the ECM commands lock-up off.
(The difference between engine speed and input turbine speed is less than 35 rpm.)

Step 1-3:

Step 3(Continued):

INSPECTION PROCEDURE

HINT: Performing the ACTIVE TEST using the hand-held tester allows the relay, VSV, actuator and so on to operate without parts removal. Performing the ACTIVE TEST as the first step of troubleshooting is one method to shorten labor time. It is possible to display the DATA LIST during the ACTIVE TEST.
a. Warm up the engine.
b. Turn the ignition switch off.
c. Connect the hand-held tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
d. Turn the ignition switch to the ON position.
e. Push the "ON" button of the hand-held tester.
f. Clear the DTC.
g. Select the item "DIAGNOSIS/ENHANCED OBD II/ACTIVE TEST/LOCK UP".




h. According to the display on tester, perform the "ACTIVE TEST".

HINT:
- This test can be conducted when the vehicle speed is 58 km/h (36 mph) or more.
- This test can be conducted with the 5th or 6th gear.




i. 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, but not fully, the accelerator pedal in order to decelerate. (Fully releasing the pedal will close the throttle valve and lock-up may be turned off automatically.)