BOLT 6I0650 - Caterpillar

Illustration 1 g02139498
View of the left side of a typical C18 Marine Engine
(1) Sensor for the fuel pressure
(2) Sensor for the fuel outlet temperature
(3) Secondary engine control module (ECM)
(4) Sensor for the air inlet temperature
(5) Boost pressure sensor
(6) Primary ECM
(7) Oil pressure sensor
(8) Crankcase pressure sensor
(9) Fuel pressure sensor
(10) Aftercooler coolant pressure (sea water)
Illustration 2 g02139500
View of the right side of a typical C18 Marine Engine
(11) Rear exhaust temperature sensor
(12) Coolant temperature sensor
(13) Unfiltered engine oil pressure sensor
(14) Front exhaust temperature sensor Failure of Sensors
All Sensors
A failure of any of the sensors may be caused by one of the following malfunctions:
Sensor output is open.
Sensor output is shorted to "- battery" or "+ battery".
Measured reading of the sensor is not within the specification.Coolant Temperature Sensor
The coolant temperature sensor monitors engine coolant temperature. The coolant temperature sensor is used by the engine system diagnostics with an output from the Electronic Control Module. The output of the ECM can indicate a high coolant temperature through a relay or a lamp. In addition, the sensor activates the cold start strategy which improves the startability of the engine.The minimum coolant temperature that will activate the alarm is 106°C (223°F). The switch opens as the coolant cools. A reset procedure is not required.Failure of the Coolant Temperature Sensor
If one of the following conditions exist, a failure of the coolant temperature sensor may have occurred:
Sensor output is open.
Sensor output is shorted to ground or supply.
Measured reading of the coolant temperature is out of the specification.The ECM will detect the failure of the coolant temperature sensor. The diagnostic lamp will warn the operator about the status of the coolant temperature sensor. Strategies that are related to the coolant temperature will be disabled if a failure occurs. The failure of the coolant temperature sensor will not cause a shutdown of the engine or any horsepower change.Engine Oil Pressure Sensor
The engine oil pressure sensor can detect engine oil pressure for diagnostic purposes. The engine oil pressure sensor sends a signal to the Electronic Control Module (ECM).Low Oil Pressure Warning
The setpoint is dependent upon the engine rpm. The fault will be active and logged only if the engine has been running for more than 15 seconds. Very Low Oil Pressure Warning
The low oil pressure setpoint is dependent upon the engine rpm. If Derate mode is selected, the ECM will derate the engine power. The engine horsepower will be limited.Failure of the Engine Oil Pressure Sensor
If one of the following conditions exist, a failure of the engine oil pressure sensor may have occurred:
The engine oil pressure sensor is open.
The engine oil pressure sensor is shorted to ground or supply.
Measured reading of the oil pressure is out of the specification.The ECM will detect the failure of the engine oil pressure sensor. The diagnostic lamp warns the user about the status of the engine oil pressure sensor. The oil pressure related strategies will be disabled. The failure of the engine oil pressure sensor will not cause a shutdown of the engine or any horsepower