27. The method of claim 16 , wherein said instructions conveyed to the onboard vehicle control network allow the onboard vehicle control network to be diagnosed through the graphical display on the portable handheld wireless diagnostic unit.
27. The method of claim 16 , wherein said instructions conveyed to the onboard vehicle control network allow the onboard vehicle control network to be diagnosed through the graphical display on the portable handheld wireless diagnostic unit. 28. The method of claim 27 , wherein the instructions force individual system components of the onboard vehicle control network into desired output states.