Abstract: An air-per-cylinder (APC) security system for a vehicle comprises an APC determination module, an APC threshold determination module, and an APC diagnostic module. The APC determination module determines first and second APC values for first and second cylinders of an engine, respectively, based on mass airflow (MAF) into the engine. The APC threshold determination module determines an APC threshold based on the first APC value and a spark timing for the first cylinder. The APC diagnostic module selectively diagnoses a fault in the APC determination module when the second APC value is greater than a sum of the first APC value and the APC threshold.

Abstract: An engine coolant temperature estimation system comprises a coolant temperature estimation module and a coolant monitoring module. The coolant estimation module estimates an engine coolant temperature based on at least one of a mass air flow, a vehicle speed, and an ambient temperature. The coolant monitoring module selectively operates an engine based on the estimated engine coolant temperature.

Abstract: A spring assembly is mounted on a crankshaft for a vehicle. A selector mechanism for the spring assembly selectively connects the spring assembly to the crankshaft. The selector mechanism is engaged in a first position to connect the spring to the crankshaft when the engine is shut-off such that the crankshaft winds the spring as it rotates. The selector mechanism is then engaged in a second position such that the spring applies a rotational force to re-start the engine. A method for braking the engine includes engaging the crankshaft with the torsion spring and winding the torsion spring with rotation of the crankshaft until the tension within the torsion spring is greater than the force applied to the crankshaft.

Abstract: A control system for an engine includes a block heater determination module, an adjustment module, and an engine control module. The block heater determination module generates a block heater usage signal based on ambient temperature, measured engine coolant temperature, and a length of time of the engine being off prior to engine startup. The adjustment module generates a temperature signal based on the ambient temperature. The engine control module determines a desired fuel mass for fuel injection at engine startup based on the temperature signal when the block heater usage signal has a first state. The engine control module determines the desired fuel mass at engine startup based on the measured engine coolant temperature when the block heater usage signal has a second state.

Abstract: A spring assembly is mounted on a crankshaft for a vehicle. A selector mechanism for the spring assembly selectively connects the spring assembly to the crankshaft. The selector mechanism is engaged in a first position to connect the spring to the crankshaft when the engine is shut-off such that the crankshaft winds the spring as it rotates. The selector mechanism is then engaged in a second position such that the spring applies a rotational force to re-start the engine. A method for braking the engine includes engaging the crankshaft with the torsion spring and winding the torsion spring with rotation of the crankshaft until the tension within the torsion spring is greater than the force applied to the crankshaft.

Abstract: A control system for an engine includes a block heater determination module, an adjustment module, and an engine control module. The block heater determination module generates a block heater usage signal based on ambient temperature, measured engine coolant temperature, and a length of time of the engine being off prior to engine startup. The adjustment module generates a temperature signal based on the ambient temperature. The engine control module determines a desired fuel mass for fuel injection at engine startup based on the temperature signal when the block heater usage signal has a first state. The engine control module determines the desired fuel mass at engine startup based on the measured engine coolant temperature when the block heater usage signal has a second state.

Abstract: An engine coolant temperature estimation system comprises a coolant temperature estimation module and a coolant monitoring module. The coolant estimation module estimates an engine coolant temperature based on at least one of a mass air flow, a vehicle speed, and an ambient temperature. The coolant monitoring module selectively operates an engine based on the estimated engine coolant temperature.