Abstract: A vehicle-mounted electronic control apparatus can automatically adjust an amount of checksum calculation to be executed at the time of each periodic processing. A checksum calculation processing section (20) for calculating the value of a checksum in a memory (4) in a divided manner at each timing (Ta) of execution of periodic processing executes one checksum calculation processing operation of a fixed number of bytes, makes a comparison between a current time (Tc) and a processing end limit time (Tb) at which the execution of the periodic processing should be ended, after execution of the checksum calculation processing operation, executes the checksum calculation processing again when a period of time from the current time (Tc) to the processing end limit time (Tb) has a margin greater than or equal to a predetermined time (Tr), and interrupts the checksum calculation processing operation when there is no sufficient margin.

Abstract: A vehicle-onboard control system for controlling various devices mounted on the motor vehicle. A control program for the control system can be altered through facilitated processing procedure with simple hardware structure while avoiding unfitness of control variables stored in a backup random access memory and used in executing the control program. A bootstrap program (13) responds to a command signal (C) issued by an external memory rewriting device (50) upon rewriting of the control program to thereby set an initialization flag (FN) in a backup RAM (14) containing control variables. The control program rewritten with updated data supplied from the memory rewriting device (50) responds to the set state of the initialization flag (FN) upon activation, to thereby initialize the control variables stored in the backup RAM (14) so that the control variables conform with the control program.

Abstract: A fuel injection control apparatus for an internal combustion engine in which the air taken into the intake manifold by a Karman vortex detector. However, the amount of fuel injected is based on a calculated intake volume. The calculated intake volume for a time interval is a weighted sum of the measured volume and the calculated intake volume of the previous period. This overaging amounts for surge storage in the intake manifold and other input paths.

Abstract: A system and a method for controlling fuel supply to an internal combustion engine are disclosed in which excessive supply of fuel to the engine is effectively prevented in a most reliable manner particularly at the time of engine deceleration. To this end, a reduction in the amount of intake air sucked into an engine per intake stroke is sensed, and the amount of fuel supplied to the engine is reduced when there is a reduction in the intake air amount sucked into engine per intake stroke. The amount of reduction in the fuel supply is changed in accordance with at least one of the number of revolutions per minute of the engine and the amount of intake air sucked into the engine per intake stroke.

Abstract: Ignition timing control system for an internal combustion engine which is constructed with an intake air quantity detecting device for detecting a quantity of air taken into the internal combustion engine, an engine revolution detecting device for detecting number of revolution of the engine, an An detecting device for calculating an output from the intake air quantity detecting device between predetermined crang angles, a correcting device for correcting an output from the engine revolution detecting device at the transition of the engine revolution, and a control device for controlling the ignition timing of the engine based on the outputs from the engine revolution detecting device and the correcting device.

Abstract: A fuel supply control apparatus for an internal combustion engine comprises a detecting means for detecting the increment of air intake quantity for the internal combustion engine and a sensor for detecting temperature of the cooling water of the internal combustion engine so that the fuel supply quantity is increased according to the temperature of cooling water when the increment of air intake quantity is detected, thereby enabling rapid increment of fuel supply quantity according to the increment of the revolution of the engine and compensation of fuel supply loss, which is caused by adhesion of liquefying fuel inside the air intake pipe and the like, according to the temperature of cooling water.

Abstract: A fuel supply control apparatus for an internal combustion engine comprises a detecting means for detecting the decrement of air intake quantity for the internal combustion engine and a sensor for detecting temperature of the cooling water of the internal combustion engine so that the fuel supply quantity is decreased according to the temperature of cooling water when the decrement of air intake quantity is detected, thereby enabling rapid decrement of fuel supply quantity according to the decrement of the revolution of the engine and compensation of fuel supply loss, which is caused by adhesion of liquefying fuel inside the air intake pipe and the like, according to the temperature of cooling water.

Abstract: An ignition timing control apparatus for an internal combustion engine has an air flow sensor for sensing the air flow rate into the air intake pipe of the engine and producing an electrical output signal in the form of pulses having a frequency which is proportional to the air flow rate, and a crank angle sensor for producing an electrical output pulse each time the crankshaft of the engine is at a prescribed crank angle. A pulse counter counts the number of output pulses from the air flow sensor between consecutive output pulses of the crank angle sensor. A controller controls the current to an ignition coil based on the engine rotational speed and on either the output of the pulse counter, or on the output of a calculating mechanism which calculates the amount of intake air into the cylinders of the engine between consecutive output pulses of the crank angle sensor based on the output of the pulse counter.

Abstract: A fuel control apparatus for a fuel injection system of an internal combustion engine has an air flow sensor for sensing the air flow rate into the air intake pipe of the engine and producing an electrical output having a frequency which is proportional to the air flow rate, and a crank angle sensor for producing an electrical output pulse each time the crankshaft of the engine is at a prescribed crank angle. A load detector detects the number of output pulses from the air flow sensor between consecutive output pulses of the crank angle sensor, and an air flow rate calculator calculates the actual intake air flow rate into the cylinders of the engine based on the output of the load detector. A controller controls the supply of fuel to fuel injectors for the engine based on the output of the calculator. The load detector includes a frequency divider which performs frequency division of the output from the air flow sensor when the load exceeds a prescribed level.

Abstract: Each of fuel injectors associated with respective cylinders of an internal combustion engine is driven several times for each air-intake with narrow drive pulses during the engine at low temperature is in a starting stage.

Abstract: A fuel supply control apparatus for an internal combustion engine, which, when an air quantity detected at a predetermined crank angle of the internal combustion engine is represented by Qa and the (n-1)th air intake quantity and the next (n)th air intake quantity of the internal combustion engine at the predetermined crank angles thereof by Qe(n-1) and Qe(n) respectively, judges the optimum fuel supply quantity of the internal combustion engine by an equation: Qe(n)=K.multidot.Qe(n-1)+(1-K).multidot.Qa with filtering using the filter constant K, and which varies the filter constant K corresponding to an operating condition of the internal combustion engine, for example reduces K during idling, so that the fuel supply quantity can be controlled most suitably during idling and loaded operation.