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:
Terminals of ecu
1. Inspect integration relay
Disconnect the connector from the integration relay.
check the continuity between each terminal of the disconnected connector
and the body ground, as
shown in the illustration and table.
Standard:
If the result is not as specified, the vehicle’s ...
Using the audio system
Optimal use of the audio system
Sound quality (treble/bass) and volume balance can be adjusted.
1 Displays the current mode
2 Changes the following setting
• Sound quality and volume balance
The sound quality and balance setting can be changed to produce the best sound.
• Automatic ...
Tire size
■ Typical tire size information
The illustration indicates typical tire size.
1 Tire use (P = Passenger car, T = Temporary use)
2 Section width (millimeters)
3 Aspect ratio (tire height to section width)
4 Tire construction code (R = Radial, D = Diagonal)
5 Wheel diameter (inches)
6 Loa ...