ACTUATOR 2790850 - Caterpillar

The information from the sensors enables the master Electronic Control Module (ECM) and the slave ECM to control the engine as efficiently as possible over a wide range of operating conditions.The sensors also enable the modules to activate alarms, derates, and shutoffs in response to abnormal operation. The functions of the sensors are described below.
Illustration 1 g01457398
Right side view (1) Detonation sensors (2) Jacket water temperature sensor (3) Inlet manifold air temperature sensor (4) Jacket water inlet pressure switch (5) Prelube pump pressure switchDetonation sensors (1 and 14) - The detonation sensors monitor the engine for mechanical engine vibrations. Each sensor monitors two cylinders. The sensor produces a voltage signal that is proportional to the engine detonation. The master ECM monitors the detonation sensors on the left bank and the slave ECM monitors the detonation sensors on the right bank. This information is processed by each ECM in order to determine detonation levels. To eliminate detonation, the master ECM or the slave ECM retards the timing of the cylinder. If detonation continues, the master ECM will shut down the engine. To observe the value of the output of the sensors, use Cat ET to view the "Cylinder #X Detonation Level". The "X" is the number for the particular cylinder.Jacket water temperature sensor (2) - The temperature sensor is located in the water temperature regulator housing. To monitor the coolant temperature, the element must be in contact with the coolant. Otherwise, the sensor will not function properly. A high coolant temperature will activate an alarm or a shutdown. A low coolant temperature will only activate an alarm. The trip points for the activation can be programmed with Cat ET. The engine can be restarted after a shutdown due to high engine coolant temperature. However, another shutdown will occur after one minute if the temperature remains high. To observe the value of the output of the sensor, use Cat ET to view the "Engine Coolant Temperature" parameter.Inlet manifold air temperature sensor (3) - A sensor for monitoring the manifold air temperature is located in the inlet elbow for the number one cylinder head. Excessive manifold air temperature can activate an alarm or a shutdown during high load or low load operation. The trip points for activation can be programmed with Cat ET. To observe the value of the output of the sensor, use Cat ET to view the "Inlet Air Temperature" parameter.Jacket water inlet pressure switch (4) - A pressure switch is located at the inlet for the engine jacket water. If the inlet pressure is too high, the switch will activate a shutdown. To observe the status of the switch, use Cat ET to view the "Engine Coolant Pump Pressure" parameter.Prelube pump pressure switch (5) - The prelube pump pressure switch is used by the control in order to indicate that oil pressure is sufficient to start cranking the engine.
Illustration 2 g01457401
Left side view (6) Pressure sensor for unfiltered oil (7) Pressure sensor for filtered oil (8) Jacket water outlet pressure