No! For years there was only a small amount of info the controller could give up. During that time a number of preformatted replies were stored for retrieval.
Much info became available in the early 90's to allow activation of components and view actual values. This became so combersome that real communications were required to use all the available functions. Systems were available with both impulse and data comunications through about 1994 depending on model and system. All systems are digital by the 1996 model year.
The EASE program
www.easesim.com is a widely sought professional tool that can be purchased in a number of formats for those without palm devices. It can be had for a single protocol for about the same as the palm programs. It can be upgraded into a serious tool, especially for the domestics with body and chassis functions. They claim that they will eventually do all cars in order of numbers manufactured.