The present disclosure relates to a coolant level sensor device for application in vehicles, comprising three interoperable component parts: a housing component, an interchangeable cartridge assembly, and a resistor pigtail. The housing component may be configured to permanently and/or semi-permanently reside within the engine cooling system such that the housing component may receive the interchangeable cartridge assembly selectively connected with the resistor pigtail. The interchangeable cartridge assembly may comprise a reed switch that may be replaceable when damaged. Further, the interchangeable cartridge mechanism may be configured to connect with the resistor pigtail, which may include at least one resistor, such that the at least one resistor may be removed from close proximity to the high temperatures generated by the engine, thus increasing the life of the resistor components. This three part configuration may allow for the easy replacement of elements of the coolant level sensor prone to failure, without the need to replace functioning components.

A coolant heating device for a vehicle includes: a housing storing coolant therein and having a sheath heater therein; an upper space part protruding upwards from a top surface of the housing and having an inner space via which an inner space of the housing communicates with the upper space part; a water-level-sensing part disposed inside the upper space part to sense a level of coolant in the housing; and a controller for controlling operation of the sheath heater based on the level of coolant sensed by the water-level-sensing part.

Methods and systems are providing for improving engine coolant level estimation to reduce engine overheating. The level of fluid in a coolant overflow reservoir is inferred based on the fluid level in a hollow vertical standpipe fluidically coupled to the reservoir at top and bottom locations, while the fluid level in the standpipe is estimated based on echo times of an ultrasonic signal transmitted by a sensor positioned in a recess at the bottom of the vertical standpipe. Engine power is limited differently based on distinct coolant level states determined based on a change in level of coolant in the reservoir over a duration.

Provided is fluid reservoir comprising a body having an inlet, an outlet, a fill aperture, and a fluid level indicator assembly. The fluid level indicator assembly is configured such at least an upper portion thereof extends external and above the body of the coolant reservoir. The fluid level indicator assembly includes a housing having a lower portion which extends into an interior volume of the body, and an upper portion, which is the portion that extends external and above the body.

Methods are provided for optimizing usage of water harvested or generated on-board a vehicle. An amount of water selected for injection or spraying purposes, as well as an order of water injection responsive to various vehicle operating conditions, is varied based on the amount of water to be delivered, as well as a current water level relative to a predicted future water level. The method allows water usage benefits to be maximized particularly when water availability is limited.

A coolant heating device for a vehicle includes: a housing storing coolant therein and having a sheath heater therein; an upper space part protruding upwards from a top surface of the housing and having an inner space via which an inner space of the housing communicates with the upper space part; a water-level-sensing part disposed inside the upper space part to sense a level of coolant in the housing; and a controller for controlling operation of the sheath heater based on the level of coolant sensed by the water-level-sensing part.

Methods and systems are provided for maintaining a desired engine coolant level and a relative glycol amount in the engine coolant by using water sourced from on-board vehicle systems. In one example, a method may include supplying water to the engine coolant reservoir in response to the engine coolant level decreasing below a threshold. Also, a relative glycol amount in the coolant may be maintained at a threshold amount by adding water to the coolant in response to a relative glycol increasing above the threshold.

Methods and systems are providing for improving engine coolant level estimation to reduce engine overheating. The level of fluid in a coolant overflow reservoir is inferred based on the fluid level in a hollow vertical standpipe fluidically coupled to the reservoir at top and bottom locations, while the fluid level in the standpipe is estimated based on echo times of an ultrasonic signal transmitted by a sensor positioned in a recess at the bottom of the vertical standpipe. Engine power is limited differently based on distinct coolant level states determined based on a change in level of coolant in the reservoir over a duration.

Methods and systems are provided for maintaining a desired engine coolant level and a relative glycol amount in the engine coolant by using water sourced from on-board vehicle systems. In one example, a method may include supplying water to the engine coolant reservoir in response to the engine coolant level decreasing below a threshold. Also, a relative glycol amount in the coolant may be maintained at a threshold amount by adding water to the coolant in response to a relative glycol increasing above the threshold.

Methods and systems are provided for maintaining a desired engine coolant level and a relative glycol amount in the engine coolant by using water sourced from on-board vehicle systems. In one example, a method may include supplying water to the engine coolant reservoir in response to the engine coolant level decreasing below a threshold. Also, a relative glycol amount in the coolant may be maintained at a threshold amount by adding water to the coolant in response to a relative glycol increasing above the threshold.