0390987 JOHNSON BUSH AND SEAL SERVICE PACKAGE

Illustration 1 g01137029
Front View
(1) Engine oil pressure sensor
(2) Coolant level sensor
(3) Secondary speed/timing sensor
(4) Primary speed/timing sensor
Illustration 2 g01137056
View A-A
(5) Fuel pressure sensor
(6) Fuel temperature sensor
Illustration 3 g01137058
Top View
(7) Inlet air pressure sensor
(8) Inlet air temperature sensor
(9) Coolant 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 outside of the specification.Coolant Level Sensor
Note: Coolant level sensor (7) is an optional feature.The coolant level sensor monitors the level of the engine coolant. The coolant level sensor is used to detect a condition when the coolant level is low. 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.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 to this value when the engine is shipped by Caterpillar."DISABLED" - The system will not monitor the input from the coolant level sensor. All of the diagnostics that are associated with the coolant level sensor will be disabled.See the Operation and Maintenance Manual, "Customer Specified Parameters" for more information about programmable options.Failure of the Coolant Level Sensor
A failure of the coolant level sensor will not cause a shutdown of the engine or any horsepower change.Coolant Temperature Sensor
Coolant temperature sensor (9) monitors engine coolant temperature. This feature is used for all engine system diagnostics with outputs from the ECM. The output of the ECM can indicate a high coolant temperature through a relay or a lamp.
Table 1
Coolant Temperature Sensor
Activation temperature for the high coolant temperature fault 103°C (217°F)
Activation temperature for the very high coolant temperature fault 106°C (229°F) Failure of the Coolant Temperature Sensor
The ECM will detect a 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 sensor will be disabled if a failure occurs. A failure of the coolant temperature sensor will not cause a shutdown of the engine or any horsepower change.Engine Oil Pressure Sensor
Engine oil pressure sensor (4) is an absolute pressure sensor that measures the engine oil pressure in the main oil gallery. The engine oil pressure sensor detects engine oil pressure for diagnostic purposes. The engine oil pressure sensor sends a signal to the ECM.
Table 2
Engine Oil Pressure Sensor
Operating range for the engine oil pressure sensor 0 to 690 kPa (0 to 100 psi) Low Oil Pressure Warning
The setpoint is dependent upon the engine speed. 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 speed. If the DERATE mode of the engine monitoring system is selected, the ECM will derate the engine power. The engine horsepower will be limited.Failure of the Engine Oil Pressure Sensor
The ECM will detect failure of the engine oil pressure sensor. The diagnostic lamp warns the user about the status of the engine oil pressure sensor. The engine oil pressure related strategies will be disabled in the event of a failure of the engine oil pressure sensor. A failure of the engine oil pressure sensor will not cause a shutdown of the engine or any horsepower change.Engine Oil Temperature Sensor
Engine oil temperature sensor (3) monitors the temperature of the engine oil. The ECM uses the information from the engine oil temperature sensor in order to adjust the timing of the fuel injection and the pressure of the fuel injection. The engine oil temperature sensor is also used by the ECM in order to determine initiation of Cold Start Strategy.
Table 3
Engine Oil Temperature Sensor
Operating range for the engine oil temperature sensor −40 to 120°C (−40 to 258°F) Engine Speed/Timing Sensor
The engine speed/timing sensors provide information to the Electronic Control Module (ECM) by generating pulse signals as the timing reference ring rotates past the sensor pickups. If the ECM does not receive a signal from primary speed/timing sensor (10), the "DIAGNOSTIC" lamp will indicate a diagnostic fault code which will be logged in the ECM memory. If the ECM does not receive a signal from the primary speed/timing sensor, the ECM will read the signal from secondary speed/timing sensor (6). The ECM continually checks in order to determine if there is a signal from both sensors. If either sensor fails, the faulty sensor should be replaced.Intermittent failure of the sensors will cause erratic engine control.