CORE AS-RADIATOR 4P6508 - Caterpillar

Sensor Locations
Illustration 1, Illustration 2, Illustration 3, and Illustration 4 show the typical locations of the sensors for a 3176B Industrial Engine. Specific engines may appear different from the illustrations due to differences in applications.
Illustration 1 g00578923
Right side view of engine
(1) Oil pressure sensor
Illustration 2 g00578926
Left side view of engine
(2) Fuel temperature sensor
(3) Fuel pressure sensor
Illustration 3 g00578927
Front view of engine
(4) Coolant temperature sensor
(5) Speed/timing sensor
Illustration 4 g00578924
Top view of engine
(6) Atmospheric pressure sensor
(7) Inlet manifold air temperature sensor
(8) Inlet manifold air pressure 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 out of specification.Atmospheric Pressure Sensor
Atmospheric pressure sensor (6) measures the atmospheric pressure in the crankcase. A signal is sent to the Electronic Control Module (ECM).
Table 1
Atmospheric Pressure Sensor
Operating pressure range for the atmospheric pressure sensor 0 to 116 kPa (0 to 16.8 psi) Coolant Temperature Sensor
Coolant temperature sensor (4) monitors engine coolant temperature. This feature is used for engine system diagnostics with an output from the ECM. The output of the ECM can indicate a high coolant temperature through a relay or a lamp.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. Coolant temperature related strategies 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
The engine oil pressure sensor (1) is mounted in the front of the cylinder block. There is no oil line that is connected to the sensor. Low oil pressure closes the switch. The oil pressure sensor senses oil pressure at the bearing oil gallery. There is no resetting procedure.Note: The oil pressure switch may close at 48 to 62 kPa (7 to 9 psi) below the actual trip point.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 Speed/Timing Sensor
If the ECM does not receive a signal from engine speed/timing sensor (5), the "DIAGNOSTIC" lamp will indicate a diagnostic fault code which will