The ICP (Intake Pressure Control) Sensor monitors the intake manifold pressure of a diesel engine, providing information to the ECU (Engine Control Unit). If it senses too much air in the system, it triggers an alarm and shuts down the engine. This is important because a high level of air will cause an imbalance in fuel/air ratio which can lead to insufficient power output from the engine. Without proper input from this sensor, engines may not be able to reach their full potential or even turn off completely due to lack of airflow. To prevent these problems, regular maintenance should be carried out on any vehicle with an ICP Sensor installed as part of its internal combustion system. Taking steps such as regularly cleaning and checking for debris or dust within the intake pipe that could potentially block up essential parts like sensors should ensure that vehicles are operating at optimal levels all year round.