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.

Fig 1: Shift Solenoid Valve SLU Components And Pressure VS Current Graph

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, valve body and torque converter clutch mechanical problems.

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