Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Camshaft position ”a” actuator
circuit / Circuit description
Toyota Corolla (E120): Circuit description
The variable valve timing (vvt) system includes the ecm, the oil control valve (ocv) and the vvt controller.
The ecm sends a target ”duty–cycle” control signal to the ocv. This control signal, applied to the ocv, regulates the oil pressure supplied to the vvt controller. Camshaft timing control is performed based on engine operation conditions such as the intake air volume, throttle position and engine coolant temperature.
The ecm controls the ocv, based on the signals output from the sensors. The vvt controller regulates the intake camshaft angle using oil pressure through the ocv. As result, the relative position between the camshaft and the crankshaft is optimized, and the engine torque improves, fuel economy improves, and exhaust emissions decrease under overall driving conditions. Also, the ecm detects the actual valve timing using signals from the camshaft position sensor and the crankshaft position sensor, and performs the feedback control. This is how target valve timing is verified by the ecm.
Monitor description
After the ecm sends the ”target” duty–cycle signal to the ocv, the ecm monitors the ocv current to establish an ”actual” duty–cycle. The ecm detects a malfunction and sets a dtc when the actual duty–cycle ratio varies from the target duty–cycle ratio.
Monitor strategy
Typical enabling conditions
Typical malfunction thresholds
Component operating ra
Wiring diagram
Other materials:
Fuel consumption information
Fuel consumption information
can be displayed on the
audio system screen.
System components
Audio system screen
Consumption
■ Trip information
1. Select on the main menu.
2. Select "Trip information".
If a screen other than "Current" is
displayed, select "Current".
The image is an example ...
Inspection procedure
Hint:
when the throttle position is slightly opened (the accelerator pedal
is slightly depressed) because a
floor carpet is overlapped on the accelerator pedal, or if not fully
releasing the accelerator pedal, etc.,
Dtc p505 will possibly be detected.
Read freeze frame data using the ...
Update contacts from phone
Operation methods differ between PBAP compatible and PBAP incompatible but OPP
compatible Bluetooth® phones.
If your cellular phone is neither PBAP nor OPP compatible, the contacts cannot
be transferred.
■ For PBAP Compatible Bluetooth® Phones
1 Select “Update Contacts from Phone” ...