Methods are provided for engine coolant system diagnostics. In one example, engine coolant system malfunction is indicated based on an engine coolant temperature inference model, whereas in another example engine coolant system malfunction is indicated based on a time-based monitor, where the inference model is enabled at ambient temperatures above a predetermined threshold, and where the time-based monitor is enabled at ambient temperatures below the predetermined threshold. In this way, accurate engine coolant system diagnosis may be accomplished under ambient temperature conditions wherein the engine coolant temperature inference model may be compromised.

Methods are provided for engine coolant system diagnostics. In one example, engine coolant system malfunction is indicated based on an engine coolant temperature inference model, whereas in another example engine coolant system malfunction is indicated based on a time-based monitor, where the inference model is enabled at ambient temperatures above a predetermined threshold, and where the time-based monitor is enabled at ambient temperatures below the predetermined threshold. In this way, accurate engine coolant system diagnosis may be accomplished under ambient temperature conditions wherein the engine coolant temperature inference model may be compromised.

A system that may include an engine, and a fan configured to vary a measured engine temperature of the engine during operation. A vehicle controller may also be provided having one or more processors that may be configured to determine an ice risk characteristic of the engine, operate the fan to cool the engine based on the ice risk characteristic, and operate the fan to rotate in reverse based on the ice risk characteristic.

A system that may include an engine, and a fan configured to vary a measured engine temperature of the engine during operation. A vehicle controller may also be provided having one or more processors that may be configured to determine an ice risk characteristic of the engine, operate the fan to cool the engine based on the ice risk characteristic, and operate the fan to rotate in reverse based on the ice risk characteristic.

Methods and system for providing heat to a vehicle are presented. In one example, a heat pump supplies thermal energy to an engine to reduce engine emissions during engine starting. Further, heating the engine via the heat pump may also reduce engine friction at colder ambient temperatures where oil viscosity may be increased.

A multi-mode powertrain system is described, and includes an internal combustion engine having stop/start capability. A method for controlling the multi-mode powertrain system includes circulating coolant to a heater core via an engine fluidic circuit that includes a water jacket of the internal combustion engine when temperature of the coolant is less than an engine fluidic circuit upper temperature threshold and the engine is in an ON state. Coolant is circulated to the heater core via a bypass fluidic circuit that excludes the water jacket of the internal combustion engine when temperature of the coolant is greater than a bypass fluidic circuit lower temperature threshold when the engine is in an OFF state.

An integrated coolant heating module for a vehicle includes a water-cooled condenser having a plurality of refrigerant inlet/outlet ports and a plurality of coolant inlet/outlet ports, and exchanging heat between coolant and refrigerant that circulate therein, a water heater having a plurality of mounting parts, the water heater being coupled to the water-cooled condenser and selectively heating the coolant passing through the water-cooled condenser, a multi-way valve coupled to a mounting part of the water heater, and controlling a direction of flow of the coolant, and a water pump coupled to a mounting part of the water heater, having a first side connected to the multi-way valve and a second side connected to a second coolant inlet/outlet port of the water-cooled condenser, and creating a pressure of the coolant between the multi-way valve and the water-cooled condenser.

An integrated coolant heating module for a vehicle includes a water-cooled condenser having a plurality of refrigerant inlet/outlet ports and a plurality of coolant inlet/outlet ports, and exchanging heat between coolant and refrigerant that circulate therein, a water heater having a plurality of mounting parts, the water heater being coupled to the water-cooled condenser and selectively heating the coolant passing through the water-cooled condenser, a multi-way valve coupled to a mounting part of the water heater, and controlling a direction of flow of the coolant, and a water pump coupled to a mounting part of the water heater, having a first side connected to the multi-way valve and a second side connected to a second coolant inlet/outlet port of the water-cooled condenser, and creating a pressure of the coolant between the multi-way valve and the water-cooled condenser.

A heat storage device includes a heat storage, a first flow passage, a second flow passage and a flow rate regulator. The heat storage stores heat released from coolant. The first flow passage is placed in a circulation path that conducts the coolant. The heat storage is installed in the first flow passage. The second flow passage conducts the coolant and bypasses the heat storage. The flow rate regulator adjusts a flow rate ratio that is a ratio of a second flow rate of the coolant, which flows in the second flow passage, relative to a first flow rate of the coolant, which flows in the first flow passage. The flow rate regulator reduces the first flow rate when a temperature of the coolant is decreased.

A method of controlling a fluid heater control system for a locomotive, the fluid heater control system including a heater assembly including a water pump and a heating element, the method including determining if a fuel pump of the locomotive is on, if the fuel pump is off, activating the heater assembly, running the water pump for a first predetermined period of time, determining if a temperature of the fluid is greater than a first predetermined threshold, and if the temperature of the fluid is greater than the first predetermined threshold, deactivating the water pump for a second predetermined time period.