Toyota Corolla (E120): Circuit description

The throttle pressure that is applied to the primary regulator valve (which modulates the line pressure) causes the solenoid valve slt, under electronic control, to precisely and minutely modulate and generate the line pressure according the extent of the accelerator pedal depressed or the output of engine power.
This controls the line pressure and provides smooth shifting.
Upon receiving a signal of the throttle valve opening angle, the ecm controls the line pressure by sending a predetermined (*) duty ratio to the solenoid valve, modulating the line pressure and generating throttle pressure.
(*): Duty ratio the duty ratio is the ratio of the period of continuity in one cycle.
For example, if a is the period of continuity in one cycle, and b is the period of non–continuity, then duty ratio=a/(a+b) x 100 (%)


Monitor description
The linear solenoid valve (slt) controls the transmission line pressure for smooth transmission operation based on signals from the throttle position sensor and the vehicle speed sensor. The ecm adjusts the duty cycle of the slt solenoid valve to control hydraulic line pressure coming from the primary regulator valve.
Appropriate line pressure assures smooth shifting with varying engine outputs. When an open or short in the linear solenoid valve (slt) circuit is detected, the ecm interprets this as a fault. The ecm will turn on the mil.
Monitor strategy

Typical enabling condition

Typical malfunction thresholds

Component operating range

Wiring diagram

Other materials:
Indicators
The indicators inform the driver of the operating state of the vehicle’s various
systems.
*1: Vehicles without a smart key system:
These lights turn on when the engine switch is turned to the “ON” position to indicate
that a system check is being performed. They will turn off after the ...
Circuit description
A flat type knock sensor (non–resonant type) has the structure that can
detect the vibration in a wider band
of frequency from about 6 khz to 15 khz and has the following features.
Knock sensors are fitted on the cylinder block to detect the engine knocking.
The sensor contains a piezoele ...
Circuit description
Monitor description
The ecm commands gearshift by turning the shift solenoid valves ”on/off”.
When there is an open or short
circuit in any shift solenoid valve circuit, the ecm detects the problem and the
mil comes on. Illuminating
the mil, the ecm performs the fail–safe and turns ...


