Abstract: Synchronization of relative engine angular position information is provided in the absence of an absolute engine position input signal by inducing misfires in a known engine cylinder and then monitoring misfire behavior over a test period. If significant misfire activity does not occur in an engine cylinder assumed, in accord with an assumed engine absolute position, to correspond to the known engine cylinder, then the assumed engine absolute position was not correct and is corrected through application of a position offset to the assumed position. Misfires are induced and the absolute position corrected when the engine is operating at a level assumed to be insensitive to the misfires and the correction.

Abstract: Internal combustion engine ignition timing is adjusted in response to a sensed knock condition and in response to a determination of engine knock propensity through application of fuzzy logic, wherein an inference engine comprised of a predetermined knowledge rulebase generates a set of truths in response to application of a set of input signals from a set of membership functions. The set of truths are combined according to both relative and absolute strength in indicating engine knock propensity.

Abstract: A motor vehicle has a manual transmission and means for indicating to the operator a point in operation for upshifting to the next higher gear from the present gear. A method of determining the shift point is provided based upon actual operating parameters of the motor vehicle effecting current wheel torque and predicted wheel torque in the next higher gear. Calibration to a single value representing the ratio of predicted wheel torque to current wheel torque allows simple balancing between fuel economy and performance.

Abstract: A vehicle engine utilizes adaptive knock retard in which non-volatile memory cells store slowly changed values based on sensed knock to retard ignition timing. Upon engine start, the values in one or more of the memory cells may be reduced in a proportional manner to provide a more advanced engine ignition timing more appropriate to engine warmup. The proportional reduction is based on the sensed engine coolant temperature at the initiation of engine operation, either by itself or through the difference between it and the stored engine coolant temperature from just before the cessation of the last period of engine operation.

Abstract: A traction control system provides coordinated use of axle torque management via engine spark, engine fuel, and transmission gear ratio. Primary torque management is provided by retarding the ignition timing to reduce engine torque. When the spark retard reaches a determined limit value, the vehicle automatic transmission is upshifted which reduces axle torque and engine speed, thus reducing the amount of spark retard required to control a slip condition, thereby increasing the authority of the spark retard system. The limit spark retard threshold is established as a function of the temperature of the catalytic converter so as to prevent an overtemperature condition. Further, fuel control is ultimately used if control of ignition timing is incapable of bringing the acceleration slip under control. This condition may exist, for example, when the spark system authority of control is insufficient due to limitations placed upon its authority in response to a sensed hot catalytic converter condition.

Abstract: An ignition timing system activates combustion ignition apparatus in a combustion chamber at times established at least partly in response to a knock retard value. The knock retard value is normally modified in response to a knock signal generated by a knock sensor during a knock window corresponding to a predetermined crankshaft rotational angle in which knock is to be sensed. However, if the knock signal is determined to be present at the beginning of an occurrence of the knock window, modification of the knock retard value in response to the knock signal is prevented during that occurrence of the knock window, since a knock signal already present at the beginning of the knock window is assumed to be noise.

Abstract: A method is described for adjusting the output power delivered by an internal combustion engine to compensate for variations in engine loading induced by a variable capacity refrigerant compressor of a vehicle air conditioning system. This is accomplished by estimating the change in engine loading due to the compressor, based upon an indication of the engine intake air temperature, and then, adjusting the setting of an engine output power control mechanism, in accordance with the estimate. An estimate for the change in engine loading induced when starting or stopping the variable capacity compressor is derived from a schedule of values based upon the temperature of the engine intake air. An estimate for the change in engine loading induced by the off-idle operation of the variable capacity compressor is derived as a function of the difference between the intake air temperature and a retained previous value for the intake air temperature.

Abstract: An ignition timing system generates ignition timing pulses from a basic ignition timing, a current knock retard and an adaptive knock retard. It includes a plurality of memory cells in a one-dimensional lookup table referenced to predetermined engine speeds and determines the adpative knock retard by multiplying a number derived from the cells at the current engine speed by a load gain factor based on current engine load. It updates the cells on a fixed time period basis. When sufficient knock has occurred in a time period, an increase is applied to the one or more cells closest to the engine speed at which knock first occurred during the period, with the amount of increase based on the maximum current knock retard during the period. Thus, updating is frequent and may occur even in transient conditions; and the correction is focused on the engine speed at which knock was initiated so as to prevent such knock initiation in the future.

Abstract: A throttle valve diagnostic apparatus monitors the integrity of a throttle valve position sensor in an internal combustion engine using an engine parameter indirectly related to the value position. If the absolute pressure of the air in the intake manifold associated with the throttle valve is less than a predetermined pressure for a predetermined amount of time while the position sensor indicates a valve position greater than a predetermined position, the valve position sensor is assumed to be faulty.

Abstract: A transmission controller in which the throttle position sensor signal is used to determine the throttle position so that proper shift selection may be carried out. In the event that the throttle position sensor malfunctions, a value is calculated for the throttle position based upon the manifold atmospheric pressure, then used in place of the actual value for throttle position. Such a substitution remains in effect until the throttle position sensor is properly functioning once again and the actual value for the throttle position is suitable close to the calculated value so that reversion to the actual value will occur without causing shifts that will surprise the driver who is not expecting any such shift.

Abstract: A coast-sync-coast control method for clutch-to-clutch shifting in which an engine control is employed to synchronize the engine speed with the transmission input speed at a point where the input speed would otherwise exceed the engine speed. The shift is referred to as a coast-sync-coast shift since (1) it is initiated at a coast condition where the input speed is higher than the engine speed, (2) it is completed at a synchronous condition where the speed differential across the on-coming clutch is at or near zero, and (3) a coast condition recurs immediately after the shift.

Abstract: A fuel control system for an internal combustion engine senses a failure in the coolant system and supplies fuel alternately to each of the two cylinder banks for predetermined periods of time so that one of the cylinder banks is supplied with an air and fuel mixture to power the engine and the other one of the cylinder banks is supplied with air only to be cooled thereby to extend the safe operating time of the engine. The air/fuel ratio of the mixture supplied to the bank provided with a combustible mixture is adjusted to limit the speed of the vehicle to further extend the safe operating time of the engine.