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| Illustration 1 | g01286035 |
Engine monitoring circuit | |
The components of the engine monitoring circuit are the Engine Electronic Control Module (Engine ECM), the Caterpillar Monitoring System ECM, the fuel temperature sensor, the fuel pressure switch, the fuel pressure sensor, the engine oil pressure sensor, the intake air pressure sensor, the intake air temperature sensor, the atmospheric pressure sensor, the coolant temperature sensor, the coolant level sensor and the air filter restriction pressure sensor.
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| Illustration 2 | g01259233 |
Left side view of engine (1) Engine ECM | |
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| Illustration 3 | g03689501 |
(2) Caterpillar Monitoring System ECM (behind display) (3) Engine oil pressure alert indicator (4) Air filter restriction alert indicator (5) Engine coolant level alert indicator | |
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| Illustration 4 | g01259235 |
(6) Gauge module (7) Coolant temperature gauge | |
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| Illustration 5 | g01259241 |
Left side view of engine (8) Fuel pressure switch (9) Fuel pressure sensor (10) Fuel temperature sensor | |
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| Illustration 6 | g01259242 |
Left side view of engine (11) Engine oil pressure sensor | |
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| Illustration 7 | g01259245 |
Left side view of engine (12) Intake air pressure sensor (13) Intake air temperature sensor | |
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| Illustration 8 | g01259248 |
Left side view of engine (14) Atmospheric pressure sensor | |
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| Illustration 9 | g01259249 |
Right side view of engine (15) Coolant temperature sensor | |
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| Illustration 10 | g01259610 |
Front view of engine (16) Coolant level sensor | |
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| Illustration 11 | g01268930 |
Right side view of engine (17) Air filter restriction pressure sensor | |
With the battery disconnect switch in the ON position, 24 V power is supplied from the batteries via circuit breaker 1 to Engine ECM (1).
With the key start switch in the ON position, 24 V power is supplied from the batteries via circuit breaker 6 to Engine ECM (1). Engine ECM (1) supplies 5 V power to fuel pressure sensor (9), fuel temperature sensor (10), engine oil pressure sensor (11), intake air pressure sensor (12), intake air temperature sensor (13), atmospheric pressure sensor (14), coolant temperature sensor (15) and air filter restriction pressure sensor (17). Engine ECM (1) also supplies 8 V power to coolant level sensor (16) .
With the engine running, fuel pressure sensor (9), fuel temperature sensor (10), engine oil pressure sensor (11), intake air pressure sensor (12), intake air temperature sensor (13), atmospheric pressure sensor (14), coolant temperature sensor (15) and air filter restriction pressure sensor (17), send continually changing voltage signals to Engine ECM (1). Engine ECM (1) compares these signals with the changing engine requirements and monitors the sensors are within the normal range.
If the signal from either fuel pressure sensor (9), fuel temperature sensor (10), engine oil pressure sensor (11), intake air pressure sensor (12), intake air temperature sensor (13), atmospheric pressure sensor (14), coolant temperature sensor (15) and air filter restriction pressure sensor (17) is outside normal range for the engines requirements, Engine ECM (1) will begin timing the condition. If the signals remain out of range, Engine ECM (1) will derate the engine or shutdown the engine depending on the severity of the condition.
Engine ECM (1) sends a signal to Caterpillar Monitoring System ECM (2) via the CAT Data Link. Caterpillar Monitoring System ECM (2) displays the sensor information on gauge module (6) and/or the monitoring system display of Caterpillar Monitoring System ECM (2) .
Coolant level sensor (16) sends a signal to Engine ECM (1), if the coolant level is low. Engine ECM (1) will record a fault. This fault is then sent to Caterpillar Monitoring System ECM (2) via the CAT Data Link. Caterpillar Monitoring System ECM (2) registers the fault and turns on engine coolant level alert indicator (5). Engine ECM (1) will derate the engine. If the contacts of the sensor remain open, Engine ECM (1) will shut down the engine.
Fuel pressure switch (8) sends a signal to Engine ECM (1) if the secondary fuel filter becomes plugged. This fault is then sent to Caterpillar Monitoring System ECM (2) via the CAT Data Link. Caterpillar Monitoring System (2) registers the fault and turns on the maintenance alert indicator. Engine ECM (1) will begin timing the condition. If the switch remains out of range, Engine ECM (1) will derate the engine.