US Patent 7873464 Block heater usage detection and coolant temperature adjustment

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.