Low Coolant Sensors in Action


One of the most neglected parts of any automotive engine is the cooling system, because vehicle owners tend to only pay attention to this particular item when the car has overheated. Unfortunately this is too late since a hose has burst, the radiator has sprung a leak, or the engine itself has blown a very important internal gasket, which will mean a hefty bill at the mechanic shop.

Most cars today use either an air cooled system or a fluid cooled model to keep the engine at normal operating temperatures, and this fluid has to be maintained at optimal levels. For a long time, the coolant level could only be checked when the engine was cold, so the radiator cap could be safely removed to see where the level was in the radiator itself. Trying to take off a hot cap to see where the actual level was could mean catastrophe.

It was also easier in the past, since engines were not quite as efficient and a loss of some coolant didn’t matter as much as it does today because new vehicles require a much tighter degree of maintenance. For the most part, manufacturers today have installed a simple float switch which can indicate when the coolant level falls below the minimum acceptable standard. They are extremely easy to replace and are effective at the job they were designed to do, but these parts can break down due to the twin effects of engine vibration and being constantly awash in fluid. This is the reason that automotive engineers have begun to adopt new methods of monitoring the cooling system and have come up with a solid state (no moving parts) model that will effectively end the reign of the common float switches used in the past.

They offer a number of advantages over their predecessors since all of them can be programmed to provide a number of functions in the vehicle and they are also small enough to fit almost anywhere under the hood. With the many new advantages and upgrades that are provided by these new solid state models, the cost has not risen significantly. Add to this the fact that they are extremely reliable, and most of the major car makers are now putting this brand into production with all of the new models coming out.

The newest technology uses something called capacitance to provide a much better feed back to the on board computer in the way of coolant level. It uses contact with the liquid to continually update the information instead of a steady state that was previously relied upon to provide this data. These new capacitive switches use a microprocessor (small computer chip) built into the unit itself that can be used with a great deal of different applications, but they can all be programmed internally to provide the onboard computer a great deal of effective options to use when monitoring any kind of fuel level — whether it be coolants, oils, or even fuels in some cases.

Engineers have gone a step further when designing these units, because normally an alarm would sound indicating to the user that the coolant system is in critical need of some maintenance. However, the newest models use an active response and shut down the engine before major damage can occur. Another great idea was to build a delay into the sensor in case of a false positive reading that would eliminate the need for a complete engine shutdown. This situation might occur when the vehicle was experience some bumpy roads or other turbulence that would cause the fuel to “slosh” around and make contact with the unit, signaling a problem to the onboard computer that there was trouble with the cooling system. The automotive cooling system has come a long way and users can now expect a great deal more out of the cars since technology has continued to make strides in making them safer and more reliable.

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