Abstract: A method for setting an initial compensation value of a sensor complex module is provided. The method for setting the initial compensation value of the sensor complex module including an acceleration sensor, a memory, and a controller that performs the setting of the initial compensation value, includes the following steps. A preset sensitivity value and an offset value are read from the memory, and an acceleration value is detected using the acceleration sensor. Then, an accelerating-force sensitivity value is calculated using the acceleration value and the offset value, and an accelerating-force error value is calculated using the accelerating-force sensitivity value and the sensitivity value. A gradient error value is calculated using the accelerating-force error value and the acceleration of gravity, and a polarity value is set according to the accelerating-force sensitivity value.

Abstract: A control unit calculates a quantity of air that is taken into an engine from an output current from an air flow meter that is located downstream from a throttle valve. The control unit then determines the quantity of fuel to be injected for this quantity of air. A value obtained by multiplying by two an integral value of the quantity of air from the rise point of the quantity of air until the quantity of air reaches a peak value is used for calculating the injection quantity. This value is taken as the total integrated air intake quantity of an intake stroke, and this is then divided by a predetermined air-fuel ratio so as to provide the quantity of fuel to be injected.

Abstract: Combustion failures of an internal combustion engine are controlled in closed loop fashion by sampling an engine r.p.m. to obtain a speed signal. The speed signal is subjected to a Hartley-Transformation to obtain angular frequencies or engine orders which are further processed to identify the cylinder which had a combustion failure and thereby reduced an actual engine power output compared to a rated power output. A power output correcting signal is produced and supplied to the engine. The system for performing these steps includes at least a speed signal sampler, a frequency analyzer to perform the Hartley-Transformation, a cylinder identifier or classifier and a controller which supplies the closed loop control signal to the engine.

Abstract: A signal modifying device, user interface, and method of modifying a signal. The signal modifying device includes a processor, a first input coupled to the processor and an output coupled to the processor. Instructions are stored within the processor that, when executed by the processor, cause the processor to provide a signal incident at the output that corresponds to a signal incident at the input.

Abstract: Determining a fuel injection amount of an engine system having a crank sensor and airflow sensor includes computing a speed change of engine revolutions per minute and computing a speed change of an intake-air amount. Comparing the speed change of the engine rpm and the speed change of the intake-air amount with reference values, and if vibration and reverse-flow are determined to occur in the intake manifold, correcting the intake-air amount into the present engine speed and computing the present intake-air amount. The fuel injection amount is then determined by using the above computed intake-air amount. This improves the accuracy of determining the credible range of the airflow sensor and increases the range using the airflow sensor.

Abstract: A signal conditioning device, user interface, and method of conditioning a signal. The signal conditioning device includes a processor, a first input coupled to the processor and an output coupled to the processor. Instructions are stored within the processor that, when executed by the processor, cause the processor to provide a signal incident at the output that corresponds to a signal incident at the input.

Abstract: To provide a method of processing intake air pressure signals for accurately detecting the engine load including the accelerating state and the intake air flow rate from the intake air pressure. Intake air pressure signals detected with an intake air pressure sensor 15 are processed with a low-pass filter. The low-pass filter is set to cut off frequencies that are not higher than the frequency corresponding to the wavelength that is four times the length of a pressure guide pipe 23 leading to the pressure sensor 15 and to cut off frequencies that are not lower than the driving frequency of the intake valve, which eliminates electric noises and air column vibration occurring in the pressure guide pipe 23 and makes it possible to obtain smooth and real changes in the intake air pressure commensurate with the strokes.

Abstract: A method and system for controlling fuel for an internal combustion engine. Two fuel demand signals are provided, one from an idle speed fuel controller (i.e., a base fuel demand signal) and one from pedal position (i.e., an unmodified pedal fuel demand signal). The pedal position signal is a function of engine speed and actual pedal position. A modified pedal position fuel demand signal is produced. The modified pedal fuel demand signal is equal to the unmodified pedal fuel demand increased by a bias value. The bias value is a predetermined offset, or hysteresis value, from the base fuel demand signal. The actual fuel supplied to the engine is equal to the greater of the base fuel demand signal and the modified pedal fuel demand signal. With such method, the amount of dead pedal time delay is reduced.

Abstract: A system for improving the performance of a motor vehicle internal combustion engine includes a controller positioned between an O2 sensor. The controller alters the O2 sensor signals and adjusts supplemental sensor signals received from supplemental sensors and sends the altered O2 signals and the adjusted supplemental sensor signals to a programmed electronic control unit which controls operation of fuel injectors.

Abstract: Disclosed here is a control unit employed for an internal combustion engine and provided with air flow sensor output correcting element capable of correcting a detected voltage error to occur in the air flow sensor according to a surge voltage and a supply voltage at each actuation of the thermal type air flow sensor. The thermal type air flow sensor output correcting element includes surge time measuring element for measuring a surge time in a value detected in the thermal type air flow sensor at the time of the sensor power on and supply voltage detecting means. The output correcting element thus calculates a warming-up characteristic correction amount for the thermal type air flow sensor according to the measured surge time and the detected supply voltage.

Abstract: In an estimation apparatus of an air intake flow for an internal combustion engine, an air intake flow rate fed into a portion just upstream of an intake valve at a predetermined timing before starting of fuel injection is calculated based on an output of an air flow meter. A variance in the air intake flow rate caused by the change in the intake pressure at the portion just upstream of the intake vale at the predetermined timing is calculated based on an output of a pressure sensor. The calculated air intake flow rate is added to the variance to obtain an air intake flow rate fed into a cylinder at the predetermined timing. The air intake flow rate fed into the cylinder is corrected to an air intake flow rate required for estimating an actual air intake flow based on an amount of change in the air intake flow rate fed into the cylinder at the predetermined timing.

Abstract: In an estimation apparatus of an air intake flow for an internal combustion engine, an air intake flow rate fed into a portion just upstream of an intake valve at a predetermined timing before starting of fuel injection is calculated based on an output of an air flow meter. A variance in the air intake flow rate caused by the change in the intake pressure at the portion just upstream of the intake vale at the predetermined timing is calculated based on an output of a pressure sensor. The calculated air intake flow rate is added to the variance to obtain an air intake flow rate fed into a cylinder at the predetermined timing. The air intake flow rate fed into the cylinder is corrected to an air intake flow rate required for estimating an actual air intake flow based on an amount of change in the air intake flow rate fed into the cylinder at the predetermined timing.

Abstract: An engine control device includes a reference voltage memory device (21) for memorizing reference voltage VAFS_STD of AFS (9) for controlling an engine (1) under a normal state, a comparing device (22) for comparing an output voltage VAFS from the AFS (9) when the engine (1) is stopped with the reference voltage VAFS_STD, and calculating a deviation &Dgr;VAFS, and a corrections device (23) for correcting the output voltage VAFS from the AFS (9) (based on the deviation &Dgr;VAFS so that the output voltage VAFS becomes the reference voltage VAFS_STD; A fuel injection quantity Tinj is calculated based on the output voltage VAFS_OBJ from the sensor obtained by the correction device (23), so that engine stall caused by failure of the sensor for controlling the engine is avoided.

Abstract: A method for calibrating an output signal of a mass airflow (MAF) sensor in operative communication with an induction system of an internal combustion engine is provided. The method comprises the steps of determining an engine speed value, determining a maximum MAF output signal value at the engine speed value, detecting a mean MAF output signal value at the engine speed value, and correlating the MAF output signal with an airflow rate value as a function of the MAF output signal value, mean MAF output signal value and engine speed. The present invention is particularly suited to improving the MAF sensor output of internal combustion piston engines having pulsating airflow including gaseous-fueled engines.

Abstract: The injectors (6i) allocated to the cylinders are supplied with fuel by a common injection train and their opening time is calculated and controlled by a computer. According to the invention, a) any possible overlap in the opening time of at least two injectors (6i) is detected, b) in the absence of an overlap, the fuel pressure in the train outside the opening time of the injector concerned is determined, c) if an overlap is present, the pressure of the fuel when the injector concerned is opened is determined and d) the measurement established is corrected according to a predetermined variation in the pressure of the fuel caused by the injector(s) opening.

Abstract: A system and method for controlling fuel injection of a vehicle, in which a MAP (manifold absolute pressure) sensor is used to calculate variations in intake pressure in a purge interval to perform compensation of a final fuel amount, thereby improving drive performance and minimizing fuel consumption. The system and method perform compensation of the final fuel amount in the two cases (a) where the canister is at high loading and when changing from one of an idle state and a light load state to one of a part load and a full load state, and (b) where the canister is at low loading and when changing from one of the part load state and the full load state to one of the idle state and the light load state.

Abstract: Disclosed here is a control unit employed for an internal combustion engine and provided with air flow sensor output correcting means capable of correcting a detected voltage error to occur in the air flow sensor according to a surge voltage and a supply voltage at each actuation of the thermal type air flow sensor. The thermal type air flow sensor output correcting means includes surge time measuring means for measuring a surge time in a value detected in the thermal type air flow sensor at the time of the sensor power on and supply voltage detecting means. The output correcting means thus calculates a warming-up characteristic correction amount for the thermal type air flow sensor according to the measured surge time and the detected supply voltage.

Abstract: The invention relates to a method and an arrangement for correcting a fuel quantity which is supplied to an internal combustion engine. The correction is carried out in dependence upon a first corrective value for a start phase of the engine and a second corrective value for a restart of the engine. In this way, a precise fuel precontrol can be carried out.

Abstract: To perform with high accuracy the analog-to-digital conversion of signals of an air flow meter irrespective of fluctuation of a reference voltage of an analog-to-digital conversion circuit. A thermal type air flow meter including means for measuring an intake air flow rate by heating and controlling a heating resistor and means for performing analog-to-digital conversion of an air flow rate signal of the air flow rate measurement means, which inputs a reference voltage to the analog-to-digital conversion circuit so that the reference voltage can be converted from the analog signal to the digital signal by the analog-to-digital conversion circuit, and the air flow rate signal can be corrected in accordance with the value of the reference voltage. A/D conversion of the air flow rate signal can be executed accurately even when the voltage of the reference voltage source of the A/D converter in an electrical control unit is fluctuating.

Abstract: To enable accurate detection of the alternative ambient pressure when the correction of fuel supply is carried out by the used of the value of the ambient pressure substituted by the negative pressure in the inlet pipe. The difference between the calculated alternative ambient pressure and the estimated ambient pressure (offset) is set as a plurality of functions of the number of engine revolutions and the throttle opening, and stored in the area determination section with a plurality of areas divided by each offset value. In which area the condition of the engine resides is determined from the number of engine revolution and the throttle opening and the offset corresponding to the area is supplied. The calculation section calculates the calculation base value by the use of the negative pressure PB and the offset.

Abstract: A method for calibrating a pressure sensor in a fuel metering system and a corresponding device, which enable the pressure sensor to be calibrated as precisely as possible. For this purpose, the instantaneous cooling-water temperature of the internal combustion engine is measured and the drop in the cooling-water temperature is derived therefrom as a measure for the standstill time of the internal combustion engine, the pressure sensor first being calibrated when the standstill time exceeds a predefinable minimum. Thus, an arrangement for monitoring the cooling-water temperature already present per se in the vehicle may be used to reliably and precisely calibrate the pressure sensor. Therefore, this is able to be realized very quickly and almost without extra expenses, in particular without using an additional timing supervision for measuring the standstill time.

Abstract: A fuel control method uses a MAP sensor output that is encoded to render fueling computations insensitive to microprocessor clock accuracy. The signal output of the MAP sensor is encoded as a pulse width modulated signal, the cylinder air mass is calculated as a function of the encoded MAP signal and the engine is fueled according to the calculated cylinder air mass. By using the same time scale to decode the pulse width of the MAP PWM signal as is used to time injector duration, the time scale becomes irrelevant to the actual fuel/air ratio attained.

Abstract: To enable accurate detection of the alternative ambient pressure when the correction of fuel supply is carried out by the used of the value of the ambient pressure substituted by the negative pressure in the inlet pipe. The difference between the calculated alternative ambient pressure and the estimated ambient pressure (offset) is set as a plurality of functions of the number of engine revolutions and the throttle opening, and stored in the area determination section with a plurality of areas divided by each offset value. In which area the condition of the engine resides is determined from the number of engine revolution and the throttle opening and the offset corresponding to the area is supplied. The calculation section calculates the calculation base value by the use of the negative pressure PB and the offset. When the relationship between the calculated base value and the last determined alternative ambient pressure is constant, the alternative ambient pressure is renewed by the calculation base value.

Abstract: A thermal type air flow meter includes a device for measuring an intake air flow rate by heating and controlling a heating resistor, and an analog-to-digital converter for digitizing an air flow rate signal of the air flow rate measurement device. The air flow rate measurement device inputs a reference voltage to the analog-to-digital converter so that the reference voltage can be converted from an analog signal to a digital signal, and the air flow rate signal can be corrected in accordance with the value of the reference voltage. A/D conversion of the air flow rate signal can be executed accurately even when the voltage of the reference voltage source of the A/D converter in an electrical control unit is fluctuating.

Abstract: To perform with high accuracy the analog-to-digital conversion of signals of an air flow meter irrespective of fluctuation of a reference voltage of an analog-to-digital conversion circuit. A thermal type air flow meter including means for measuring an intake air flow rate by heating and controlling a heating resistor and means for performing analog-to-digital conversion of an air flow rate signal of the air flow rate measurement means, which inputs a reference voltage to the analog-to-digital conversion circuit so that the reference voltage can be converted from the analog signal to the digital signal by the analog-to-digital conversion circuit, and the air flow rate signal can be corrected in accordance with the value of the reference voltage. A/D conversion of the air flow rate signal can be executed accurately even when the voltage of the reference voltage source of the A/D converter in an electrical control unit is fluctuating.

Abstract: To perform with high accuracy the analog-to-digital conversion of signals of an air flow meter irrespective of fluctuation of a reference voltage of an analog-to-digital conversion circuit. A thermal type air flow meter including means for measuring an intake air flow rate by heating and controlling a heating resistor and means for performing analog-to-digital conversion of an air flow rate signal of the air flow rate measurement means, which inputs a reference voltage to the analog-to-digital conversion circuit so that the reference voltage can be converted from the analog signal to the digital signal by the analog-to-digital conversion circuit, and the air flow rate signal can be corrected in accordance with the value of the reference voltage. A/D conversion of the air flow rate signal can be executed accurately even when the voltage of the reference voltage source of the A/D converter in an electrical control unit is fluctuating.

Abstract: A method and apparatus is provided for correcting the airflow in a combustion engine drawn in through an induction pipe and measured in the induction pipe. The measured airflow is multiplied by a correction factor which is formed as a function of a value expressing the degree of the measurement error and a value expressing the direction of the measurement error. Preferably, the value expressing the degree of the measurement error is obtained by calculating the standard deviation or the variance of the measured airflow. The value expressing the direction of the measurement error is determined with at least one additional operating value of the internal combustion engine.

Abstract: The engine of the present invention has a plurality of cylinders that are divided into a first group and a second group. An air flow meter for detecting an amount of air supplied to the engine is provided downstream of an air cleaner in an intake system. A crank angle sensor for detecting a rotational speed of the engine is provided adjacent to a crank shaft. The amount of air distributed to the first group and the amount of air distributed to the second group are calculated based on the detected amount of air and the detected rotational speed of the engine. The amount of fuel injected into the first group and the amount of fuel injected into the second group are corrected according to the calculated amounts of air distributed to the first and second groups.

Abstract: An electronic engine control system for a lean burn engine includes a unit for detecting an amount Qa of intake air fed into a cylinder of the engine, a unit for detecting an engine speed Ne, a unit for calculating a basic fuel injection pulse width TPbas on the basis of the intake air amount Qa and the engine speed Ne, and a unit for determining control parameters containing any of at least an air-fuel ratio, an ignition timing, a fuel injection timing, a throttle opening and an EGR rate in accordance with an operating state of the engine in optimum. A reference TPref having the same dimension as the basic fuel injection pulse width TPbas and which is a function of an accelerator operating amount determined on the basis of the accelerator operating amount is determined as a load parameter used upon determination of the control parameters of the engine in operation with a lean air-fuel ratio. Because the accelerator opening amount is inputted to calculate the reference .sub.

Abstract: An engine management system for 4-cycle engines includes a processing means and utilizes various inputs from sensors operatively connected to the engine for the purpose of providing the correct fuel/air ratio or spark ignition angle for the engine in a manner whereby the transient response is fast. The engine management system utilizes the rotational speed information that is obtained from a magneto or speed sensor to determine the speed of each engine revolution. The system effectively solves many of the fuel/air ratio problems that are caused by load transients occurring on the engine. By comparing such high pass filtered speeds of selected revolutions, the system is able to determine the inferred engine intake air flow. By using measured system rotational inertia compensation factors for the engine together with the inferred intake air flow, the system can accurately determine the amount of fuel to be fed to the engine for proper operation.

Abstract: A device and method for controlling the amount of fuel supplied to an internal combustion engine as a function of operating characteristics such as the pressure in the intake manifold, the engine speed, coolant temperature and intake air temperature, where a load signal formed from pressure and engine speed values is corrected by a correction factor F.sub.CORR as a function of the temperature, and when forming the correction factor F.sub.CORR, the influences of the engine temperature and/or the intake air temperature on the load sensing are weighted separately as a function of the operating point.

Abstract: An electrical apparatus which does not require intervening combinational logic devices to condition signals produced by a computer prior to applying same to the switching devices for an electrical end device, such as a electric motor or the like is described. Controllers incorporating the electrical apparatus can be interconnected in a peer-to-peer arrangement permitting each controller to communicate with any or all of the other controllers within the network. Various types of devices, such as input/output devices, personal computers, sensors incorporating logic, etc.

Abstract: It is intended to automatically correct for ignition timing of the engine and fuel injection timing of the engine even if they changed in the case where the attached position of a cam angle sensor is offset after change of distributors and therefore the reference angle is offset. The crank angle and the cam angle of an engine are detected. The phase difference between these angles is computed. The result is reflected in the ignition timing and the fuel injection timing.

Abstract: The invention provides a process and apparatus for controlling combustion in an Otto combustion engine in which the control variables that control combustion are determined for a particular power cycle as a function of the detected combustion course of a preceding power cycle. According to the invention, a desired burn-through function value for a particular power cycle is precalculated based on values of pertaining influence factors detected in a preceding power cycle, to determine an actual burn-through function value of the particular power cycle in real time. The desired burn-through function is compared with the actual burn-through function and actualized values for the burn-through function influence factors are determined. These factors are used to determine the control variable values for a subsequent power cycle.

Abstract: In a direct injection type gasoline engine for directly injecting fuel into each cylinder, fuel pressures supplied to each fuel injection valve are detected, and the fuel injection pulse width is detected according to the detected fuel pressures. Here, the fuel injection pulse width is corrected based on a value obtained by smoothing the detected values of the fuel pressures and at the same time, a smoothing level is changed according to the transitional or steady state of the engine, thereby achieving the response characteristic of correction at the transitional state and the stable correction at the steady state.

Abstract: A method and apparatus for controlling air/fuel ratio of an internal combustion engine at a desired level of richness or leanness utilizes an existing air flow sensor for sensing air flow into the engine and generating a corresponding air flow signal. A signal multiplier multiplies the air flow signal by a constant to generate a modified air flow signal corresponding to the desired level of richness or leanness. A control signal is then generated for controlling the air/fuel ratio to the desired level.

Abstract: An engine speed control system for an engine of the type having a throttle position sensor for outputting throttle position data, from which engine control parameters are determined, is disclosed. In accordance with this system, an output value of the throttle position sensor is obtained. If the output value is within a predetermined range, an adjustment value is calculated. If the adjustment value is within a predetermined range, a new throttle position value is calculated based on the output value of the throttle position sensor as adjusted by the adjustment value. Engine control parameters, such as timing and fuel injection volume, are then determined based on the adjusted throttle position value.

Abstract: A device for load detection with altitude adaptation is described, wherein the load is determined based on an altitude-dependent main load signal and a collateral load signal not dependent on the altitude. In connection with defined driving conditions it is possible to detect an altitude deviation by comparison of the main load signal with the collateral load signal. The result of the comparison is integrated in an integrator with a variable time constant to form an adaptation factor, by means of which the collateral load signal is then corrected. The time constant of the integrator is changed in such a way that an altitude adaptation takes place as a function of the maximally possible altitude error.

Abstract: Electronic system for calculating injection time in which an electronic unit with microprocessor receives as input a multiplicity of signals measured in the engine and a signal proportional to the engine load, for example a signal generated by a pressure sensor arranged in the intake manifold of the engine. The electronic unit comprises a circuit for compensating for the delay times due to the response inertia of the engine load sensor, the conditioning (filtering, conversion and processing) of the load signal and physical actuation of the injection. The electronic unit also comprises a circuit for the dynamic compensation of the "film/fluid" effect.

Abstract: A hydrogen and natural gas fuel mixture for internal combustion engines is provided for vehicle engines such as those used in standard production engines for automobiles, trains and lawn mowers. The gaseous fuel for operating a vehicle combustion engines includes approximately 21 to 50% Hydrogen and the rest natural gas constituents such as combinations of Methane, Carbon Dioxide, Nitrogen, Ethane, Propane, Iso-Butane, N-Butane, Iso Pentane, N-Pentane, and Hexanes Plus. A fuel mixture of approximately 28 to 36 percent Hydrogen and a air fuel equivalence ratio of approximately 0.625 is an extreme lean burn condition that yields hydrocarbon emission levels of less than approximately 104 ppm (0.84 hm/hp hr.). Current internal combustion engines that are in mass production can take this alternative fuel without any substantial modifications to their systems. This alternative fuel is lean burning and emits emissions that are below current legal standards.

Abstract: A method for comprehensive integrated control of a compression-ignition internal combustion engine having integral fuel pump-injectors utilizing an electronic control unit is disclosed. The control strategy integrates various functions of engine control including fuel delivery, cooling fan control, engine speed governing and overspeed protection, engine braking, torque control, and vehicle speed diagnostics and control. Cooling fan control is integrated with vehicle speed diagnostics and control as well as fuel delivery to provide an integrated cruise control function which incorporates engine braking. The method also includes improved control over the various engine speed governors while improving idle quality by balancing the power delivered by each of the engine cylinders when at idle. The integrated torque control employs functions to reduce NOx emissions and noise utilizing adaptive fuel delivery timing and a split injection strategy.

Abstract: A method and an apparatus for sensing an air flow into a cylinder of an internal combustion engine are arranged to determine a number of revolutions of the engine, determine a pressure of an intake pipe of the engine, and calculate an air flow Qc into a cylinder of the engine, based on the number of revolutions and the pressure of the intake pipe by the linear expression of Qc=.alpha.P+.beta., in which .alpha. is a coefficient indicating a gradient of a linear expression and defined according to the number of revolutions, .beta. is a coefficient indicating an offset value and defined according to the number of revolutions, and P is a pressure of the intake pipe. The method and the apparatus for controlling fuel of the internal combustion engine operate to generate a fuel flow signal according to the air flow into the cylinder determined by the above method and feed fuel to the internal combustion engine at a flow rate corresponding to a fuel flow signal.

Abstract: A smart mass gas flow sensor is having a housing with a bore through which a gas flows in which a sensor in the housing generates an analog signal proportional to the mass gas flow through the housing bore. A digital processor digitally processes the analog signal from the sensor and generates a substantially linear output signal representative of the mass gas flow through the housing bore.

Abstract: An fuel injection control system suitable for use with internal combustion vehicle engines fueled by compressed natural gas or the like. A liquid-fuel type closed-loop system, modified for gaseous fuel, establishes the duration of each injection command signal by the combination of a P.I.D. controller responsive to the level of exhaust oxygen, an adaptive table which stores previously determined fuel delivery rate values for particular engine speed and load conditions, an injector supply voltage table and an added table modifies the fuel delivery rate correction values which compensate for unwanted pressure variations which occur in the fuel supply due to injector sequencing effects, firing order, fuel flow effects, temperature effects, and fuel sensor errors.

Abstract: A delta model is used to calculate a predicted manifold absolute pressure MAP for a future period and the air mass induced in each cylinder is calculated from such a predicted value and used to determine the correct amount of fuel to inject at that period. Several reference pulses generated for each crankshaft revolution establish one or more sets of equally spaced points at which measurements are made of the parameters MAP, throttle position, exhaust gas recirculation value and idle air control. A base value of MAP is calculated, trends of changes in the parameters are calculated for each set of points, and weighted values of the trends are summed with the base value to predict a value of MAP. Alternatively, mass air flow MAF is measured as well as the other parameters and mass air per cylinder MAC is calculated.

Abstract: An altitude determining apparatus for an automotive vehicle includes a calculating part for determining a reference flow rate based on a throttle angle of a throttle valve and an engine speed of an internal combustion engine of the vehicle, the throttle angle being sensed from the throttle valve arranged in an intake passage of the engine and the engine speed being sensed from the engine, a correction part for detecting an operating condition under which additive gas is supplied to the intake passage downstream of the throttle valve and for changing the reference flow rate determined by the calculating part to a second reference flow rate according to the operating condition only when the above mentioned operating condition is detected, and a discriminating part for comparing an intake air flow rate sensed at an inlet portion of the intake passage with a reference flow rate supplied from the correction part and for determining an altitude condition of the vehicle based on the result of the comparison.

Abstract: A method of load and speed modifying on fuel lean-out for an internal combustion engine includes the steps of sensing a speed of the engine, determining an engine speed modifier as a function of current sensed engine speed, sensing a manifold absolute pressure (MAP) of an intake manifold of the engine, determining an engine load modifier as a function of current sensed MAP, adding the determined engine speed modifier and engine load modifier together to yield a speed/load modifier, and applying the speed/load modifier value to a fuel pulsewidth value of fuel injectors for the engine and reducing the amount of fuel injected into the engine by the fuel injectors.

Abstract: A system and method for generating a signal which indicates whether a motor vehicle containing such a system is operating on a rough road surface. The generated signal is based on the signals output by a sensor that measures the air-mass flow rate through the air-intake manifold of an internal-combustion engine. The system and method use the differences in the signals output by the sensor when on a smooth road surface and a rough road surface to generate the signal indicative of a rough road surface. The rough road indication signal can be applied, inter alia, to engine misfire detection, anti-lock braking control, and vehicle chassis regulation.

Abstract: A fuel injection amount computing unit for an internal combustion engine is disclosed, wherein when an intake air flow Qho as calculated from a throttle valve opening degree and an engine speed is greater than a predetermined value, and when a variation .DELTA.Tp.sub.REAL of a smoothed basic fuel injection amount Tp.sub.REAL is negative and a final basic fuel injection amount AvTp including phase adjustment and prefetched correction is greater than a trimmed basic fuel injection amount TrTp (=Tp.sub.REAL .times.Ktrm), a surging smoothing index ND is switched from a value (0; smoothing prohibited) corresponding to the transient state to a value (3; smoothing maximized) corresponding to the fully open state.

Abstract: A method of averaging coolant temperature for an internal combustion engine in an automotive vehicle includes the steps of sensing coolant temperature of the engine based on an output signal of a coolant temperature sensor, determining an initial value of coolant temperature based on the output signal from the coolant temperature sensor, storing the determined initial value as an initial coolant temperature value (CLTMP1) and as an averaged coolant temperature value (AVCT), periodically updating the AVCT value, and using the AVCT value to control the output of fuel injectors of the engine.