take into account the currently detected variables from the sensors and to utilize that information to determine the current performance characteristic the rate of change relative to time and whether the rate of change is within an expected range the electronic controller 20 preferably provides a real time display on the display 28 for the operator of the vehicle the display 28 preferably is a reconfigurable display that allows a vehicle operator to observe any individual detected variable or the performance characteristic determined by the electronic controller 20 additionally the system 30 preferably includes a communication port 42 that permits a service technician to utilize an external computer device not illustrated to access data from the memory portion 38 of the electronic controller 20 this feature enables a service technician to obtain information regarding the performance characteristic and the rate of change relative to time as if the service technician were in the vehicle during operation since the last visit to the service establishment having such ready access to the information determined by the electronic controller 20 provides the service technician with the ability to more quickly diagnose potential problems and to address specific portions of the vehicle that may require service without such information it is impractical for a service technician to manually inspect the large number of vehicle components that potentially could require service with this invention the service technician is able to quickly discern the portions of the vehicle that need to be addressed and serviced at a given time moreover a vehicle operator is provided with a real time display of the performance characteristic and therefore is given the ability to determine when a vehicle may need immediate service given this description those skilled in the art will be able to choose from among.