0330179 JOHNSON WASHER, Ret. spark adv.

Engines with Right-Hand Service
Illustration 1 g02213774
(1) Engine coolant temperature sensor
(2) Fuel temperature sensor
(3) Engine coolant level sensor
(4) Fuel pressure sensor
(5) Inlet air temperature sensor
(6) Inlet manifold pressure sensor
(7) Oil pressure sensor
Illustration 2 g02213775
(8) Rear turbo exhaust sensor
(9) Side turbo exhaust sensor Engines with Left-Hand Service
Illustration 3 g02213213
(1) Engine coolant temperature sensor
(2) Fuel temperature sensor
(3) Engine coolant level sensor
(4) Fuel pressure sensor
(5) Inlet air temperature sensor
(6) Inlet manifold pressure sensor
(7) Oil pressure sensor
Illustration 4 g02213775
(8) Rear turbo exhaust sensor
(9) Side turbo exhaust 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.Air Pressure Sensor for the Inlet Manifold
The air/fuel ratio control utilizes actual engine speed and actual boost pressure (inlet manifold air pressure) in order to control the transient smoke level. When the throttle increases and the engine demands more fuel, the fuel limit is controlled to reduce overall smoke levels of the engine exhaust.The Electronic Control Module (ECM) controls injection timing and the amount of fuel that is injected.The boost pressure reflects the difference in pressure between the inlet manifold air pressure sensor and the atmospheric pressure sensor (crankcase pressure).Failure of the Air Pressure Sensor for the Inlet Manifold
A failure of the air pressure sensor for the inlet manifold may have occurred if any of the following conditions are present:
The output of the air pressure sensor for the inlet manifold is open.
The output of the air pressure sensor for the inlet manifold is shorted to ground or to supply.
The reading of the air pressure sensor for the inlet manifold is out of the specification.The ECM will detect the failure of the air pressure sensor for the inlet manifold. The operator will be warned of the problem through the diagnostic lamp. The strategies that are related to the boost will be disabled. The failure of the air pressure sensor for the inlet manifold will not cause a shutdown of the engine or any horsepower change.Air Temperature Sensor for the Inlet Manifold
The air temperature sensor for the inlet manifold measures the inlet manifold air temperature. The Electronic Control Module (ECM) monitors the signal from the air temperature sensor for the inlet manifold. The output of the ECM can indicate high inlet manifold air temperature through a relay or a lamp. The air temperature sensor for the inlet manifold will not cause a shutdown of the engine or any horsepower change.Note: Heat from the inlet manifold may affect the temperature sensor for the inlet manifold. This sensor may be affected when the engine is idling and after the engine is shut off. This warm-up is due to the lack of coolant circulation through the engine and will exist until the air inside the inlet manifold cools.Coolant Level Sensor
The coolant level sensor monitors the engine coolant level. The sensor will detect coolant level. The coolant level sensor provides information to the ECM. The output from the ECM can indicate a low coolant level through a relay or a lamp. Coolant must be added to the cooling system in order to correct the condition. See the Operation and Maintenance Manual for more information.The system can be programmed with one of the following options:Enabled - The system will monitor the input from the coolant level sensor. The system is programmed with this value when the engine is shipped by Caterpillar.Disabled - The system will monitor the input from the coolant level sensor. All of the diagnostics that are associated with the coolant level sensor will be disabled.Failure of the Coolant Level Sensor
A failure of the coolant level sensor may occur under the following conditions:
The coolant level sensor is open.
The coolant level sensor is shorted to ground.
The coolant level sensor is shorted to supply.The failure of the coolant level sensor will not cause a shutdown of the engine or any horsepower change.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 103° C (217° F). The switch opens as the coolant cools. A procedure for resetting 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 very low oil pressure setpoint is dependent upon the engine rpm. If Derate mode is selected, the ECM will derate the engine power. T