Idle speed control system principle

Control principle: When the engine is idling, the throttle valve is in the fully closed position, that is, the amount of air entering the engine is no longer regulated by the throttle valve. The essence of idle speed control is to adjust the air intake through the idle speed actuator, and at the same time, with the control of fuel injection and ignition advance angle, the power generated by oil consumption in idle speed is changed to stabilize or change the idle speed.

The engine idle speed control system consists of various sensors, signal control switch, electronic control unit ECU, idle speed control valve and throttle bypass airway. ECU receives signals from relevant sensors, and sends corresponding instructions to ISCV after analysis and discrimination, so as to control the air flow in the throttle bypass and make the engine always idle at the optimal speed.

Extended data

Control strategy:

1. Provide ideal idle air volume under all possible working conditions.

2, timely compensation for engine load changes.

3. Keep the lowest idle speed and control the deceleration air volume to achieve good fuel economy.

4. Improve the emission by increasing the air volume during sudden deceleration.

5. Improve the driving performance of the vehicle.

6. The difference caused by aging of parts and the difference of each vehicle can be automatically compensated, reducing the requirement of periodic adjustment.

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