Circuit Description
WARNING: This page is about a different car, the 2002 Toyota ECHO, 2002 Toyota Celica, 2001 Toyota ECHO, and 2001 Toyota Celica. However, it is still accessible from the selected car via links, so may be relevant.
ECM uses signals from TP sensor, airflow meter and crankshaft position sensor to monitor torque converter lock-up engagement condition. ECM compares torque converter lock-up engagement condition with lock-up schedule in ECM memory to detect a malfunction with valve body, torque converter clutch or shift solenoid SL. Shift solenoid SL controls hydraulic pressure acting on lock-up relay valve, which contains torque converter clutch lock-up. DTC is set if lock-up does not occur when driving vehicle at 50 MPH or more, or lock-up remains on in lock-up off range. Possible causes:
- Shift solenoid SL is stuck open or closed.
- Valve body blocked or valve stuck.
- Lock-up clutch malfunction.