105400-7921 ZEXEL 9 420 612 422 BOSCH GOVERNOR 9420612422 1054007921

Engine Oil Pressure
The sensor utilizes engine oil pressure and engine speed to perform low engine oil pressure detection for diagnostic and annunciation.The graph below illustrates the limits of low engine oil pressure diagnostic and annunciation. The output from the ECM can be used to drive a relay or a lamp to annunciate Low Oil Pressure conditions.
Oil Pressure ParametersLow Oil Pressure Alarm
Oil pressure sensor location.The sensor is mounted in the front of the engine cylinder block with oil lines connected to the switch. Low engine oil pressure closes the switch.The oil pressure switch senses oil pressure at the bearing oil gallery. No resetting procedure is required. Switches may close at 48 to 62 kPa (7 to 9 psi) below actual trip point.Oil Pressure Sensor Failure
When the sensor output is open, shorted to ground or supply, or measured oil pressure reading is out of specification, a sensor failure may have occurred.The ECM will detect the oil pressure sensor failure and through the diagnostic lamp warn the user about the oil pressure sensor failure. The oil pressure related strategies will be disabled. The oil pressure sensor failure will not cause an engine shut down, power derating, or any engine speed change.Speed Sensing Loss Alarm
When the engine speed sensor can no longer sense engine speed, an alarm and diagnostic code entry will occur. If the ECM can not detect any engine speed, the engine will shut down.Manual Fuel Shutoff Lever
Do not use the emergency shutoff control for a normal stopping procedure.
Manual shutdown shaft with lever location.A manual shutdown shaft is provided to override the governor solenoid. This shutdown will only move the fuel control linkage to the fuel OFF position to starve the engine of fuel. It does not shut off the air inlet.Engine Shutoff Controls
Secondary shutoff controls may be electrically, mechanically or hydraulically operated. Familiarize yourself with the types and locations of the shutoff controls, the conditions which cause each control to function, and the resetting procedure required to start your engine.The shutoff controls should be tested every 1000 hours by authorized Caterpillar dealer personnel.Always determine the cause of the shutdown, and have the necessary repairs made before restarting the engine.Shutoff Solenoid Failure
When the shutoff solenoid output is open or shorted to ground or supply, a failure may have occurred.The ECM will detect open or short condition of the shutoff solenoid. If the solenoid is failed "open", the engine will shut down.The shutoff solenoid failure will cause the engine to shut down, but the pilot or service personnel can mechanically reposition the shutoff solenoid and restart the engine.Cold Start Strategy
This feature utilizes the coolant temperature sensor input to improve low temperature engine starting and warm-up. It provides quicker cold starts, smoke cleanup, reduces battery "deep" cycling and extends engine life. The engine timing is fixed at 19.5 degrees. Engine block heaters are provided to maintain minimum engine temperature when the engine is not running.When the coolant temperature is below 60°C (140°F), the cold start strategy is activated using the following parameters