Patent ID: 6283092
Filing Date: 2001-09-04
Classification: F01P,F02D,Y02T

Abstract:
A method for controlling an engine during the malfunctioning of a coolant temperature sensor, comprising the steps of:determining whether the coolant temperature sensor is malfunctioning by using information on temperature of coolant supplied from the coolant temperature sensor, information on intake air supplied from an air temperature sensor, information on engine rpm supplied from an ignition coil, information about on and off states of an ignition switch supplied from an ignition switch sensor, and information about a throttle valve opening supplied from a throttle valve switch;determining whether the engine is stalled when the coolant temperature sensor is determined to be malfunctioning;setting, when the engine is determined to be not stalled, an initial value of information on the coolant temperature as a target value of information on the coolant temperature and determining whether a start mode is canceled, the target value of information on the coolant temperature being previously established by a predetermined value in preparation for the engine being stalled;determining whether the air temperature sensor is malfunctioning when the start mode is not canceled;setting, when the air temperature sensor is outputting information normally, the information on the air temperature as a target value of information on the air temperature and performing addition and subtraction operations on the initial value of information on the coolant temperature and updating and learning the initial value of information on the coolant temperature with new information on the coolant temperature until the initial value of information on the coolant temperature reaches the target value of information on the coolant temperature; andoutputting an engine control signal according to newly learned information on the coolant temperature, and when the newly learned information on the coolant temperature reaches the target value of information on the coolant temperature, terminating the updating of the initial value of information on the coolant temperature, and outputting an engine control signal to start the engine and to control idling of the engine after the engine is started by using the target value of information on the coolant temperature as the final learned information on the coolant temperature.