CIRCLE GP 3909852 - Caterpillar

Illustration 7 g00110148
Marine transmission oil temperature sensorThe marine transmission oil temperature sensor measures the temperature of the oil in the marine transmission. The ECM uses the information from the sensor in order to diagnose a fault. The information is also used to warn the operator of excessive marine transmission oil temperature.The maximum allowable marine transmission oil temperature is 50 to 120°C (122 to 248°F). The ECM will indicate high marine transmission oil temperature through the diagnostic lamp, and the ECM will log a fault.Throttle Position Sensor
The Throttle Position Sensor (TPS) sends a signal to the ECM. The signal from the TPS is required in order to govern engine speed. The signal from the TPS is used by the ECM in order to calculate the desired engine speed. The TPS is calibrated during the initial installation of the engine.Failure of the Throttle Position Sensor
An intermittent failure in the TPS causes the engine speed to vary erratically. The ECM will perform the following process:
The ECM will detect the failure of the TPS.
The ECM will warn the operator of the failure through the diagnostic lamp.
The ECM will set the desired engine speed to low idle.If a TPS fails in a twin engine application, the operator can use a synchronization switch to transfer the throttle control to the second TPS. Both engines can then be controlled with the second throttle. If both throttle position sensors fail, the engine speed will be reduced to low idle.Fuel Temperature Sensor
Illustration 8 g00107961
Fuel temperature sensorThe fuel temperature sensor monitors the fuel temperature. Fuel temperature is monitored in order to adjust the fuel rate so that the engine will deliver consistent power. The fuel temperature sensor can also be used to warn the operator of excessive fuel temperature. A high fuel temperature can adversely affect the engine performance.Fuel Pressure Sensor
Illustration 9 g00107983
Fuel pressure sensorThe fuel pressure sensor monitors the fuel filter outlet pressure. Low fuel pressure or high fuel pressure will not cause a shutdown of the engine or any horsepower change. Fuel pressure that is outside of the normal range will affect the engine performance. If the fuel filter outlet pressure is low, the fuel filter may need to be replaced.Inlet Air Temperature Sensor (If Equipped)
Illustration 10 g00107984
Inlet air temperature sensorThe inlet air temperature sensor detects the temperature of the air that is passing through the inlet manifold. A signal is sent to the Electronic Control Module (ECM) for interpretation. The output of the ECM can indicate high inlet manifold temperature through a relay or a lamp. The inlet air temperature sensor will not cause a shutdown of the engine or any horsepower change.The ECM uses the information from the inlet air temperature sensor in order to accurately control the emissions levels of the engine. As the inlet manifold air temperature changes, the fuel injection timing is advanced. This is done in order to maintain the exhaust emission standards.Note: The reading from the inlet air temperature sensor may be significantly higher than the actual temperature of the air inside the