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.
Throttle pressure is applied to primary regulator valve, which modulates line pressure, and causes shift solenoid SLT to precisely modulate line pressure according to accelerator pedal effort, or engine power output detected. This reduces fluctuation of line pressure and provides smooth shifting. Upon receiving throttle valve opening angle signal, ECM controls line pressure by sending predetermined duty cycle ratio to shift solenoid SLT, activating solenoid, modulating line pressure and generating throttle pressure. DTC is output when voltage at SLT- terminal at ECM is zero or 12 volts for one second or more, indicating a solenoid duty cycle is not present. Possible causes:
- Open or short in shift solenoid SLT circuit.
- Shift solenoid SLT malfunction.
- ECM malfunction.