I am dealing with 785C and 789C, just wondering why for fuel filter it just using switch to determine if it is plugged. the setting is 20 psi for Fuel Filter Plugged events to be triggered. Why dont Caterpillar put pressure differential sensor instead of switch? So there is a real time monitoring via VIMS to know exactly the current fuel filter restriction in terms of differential pressure. This will also very helpful for maintenance practice which open a chance to do a replace-on-condition on the filters since mechanics know exactly whether or not the filters are already highly restricted and need to be replaced. If fuel quality is just fine, fuel filter will take longer period to be plugged, no need to change it on scheduled PM. Cost will be saved right?

I believe this is a safety feature

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It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)