Abstract: A vehicle engine control having an automatic start and stop feature for idling the engine to maintain the battery charge includes adjustment for the battery voltage threshold at which the engine is started to recharge the battery. Preferably, the adjustment results from use of an ambient air temperature sensor and a look up table in the control that varies the threshold based on a predetermined relationship between battery voltage and ambient air temperature.

Abstract: A method for controlling an internal combustion engine having a variable geometry turbocharger (VGT) and an exhaust gas recirculation (EGR) system in the face of sensor failures and mechanical faults includes generating accurate substitute values for use by the engine control logic when EGR and VGT system-related sensors are diagnosed as having failed during operation, and maintaining controlled performance of the VGT system in the face of sensor failures or mechanical faults associated with the EGR or VGT system.

Abstract: A method and system for indirectly estimating ambient air temperature. The ambient air temperature is estimated based on filtering a temperature input from a turbocharger air inlet sensor. The filtering includes compensating for engine compartment temperature variations which vary relative to the actual ambient temperature.

Abstract: A method of acquiring population data from engine control modules provided with a memory for storing data relating to parameters of engine operation. The method includes the steps of downloading stored data from a plurality of engine control modules when the engine control modules are reprogrammed. A set of population data is developed and communicated to a central database. The population data is statistically analyzed when a statistically significant portion of the population is obtained. The statistical analysis of the population data is then used to make engine design modifications, provide warranty problem analysis, and analysis of optional feature acceptance.