If the TCU isn't reset, or if its reset and the service wasn't actually done, the parameters, and calibration of the system is all out of whack. I've gotten to watch the setup process post clutch install, and felt the differences in shifting due to the calibrated settings and its all pretty impressive. After the clutch is installed, the technician test drives the car with the computer hooked up, and calibrates the system during the test drive. If there is ever a problem, they do the same process with data logging, which the raw output file can be sent to MNA, for their engineers to look at and help diagnose or confirm a problem. I have seen the files before, while helping my Italian technician friend that hates computers get them sent to Maserati. I'm not really sure what everything was, but the output is *extensive*.
This is one of the reasons I so often suggest to take the car to a dealer for work. Regardless of your opinion of the prevelance of computers in cars, and these systems making it hard to work on your own car, or even for third party shops to pop up, the reality is that as much technology has gone into the brain of the car for service related concerns as performance. In the end, its a huge advantage for the company to know exactly what part of a system is failing, cutting down diagnosis time and repair costs for warranty work. This same system that saves them money will save you money in the long run. It will also mean you have your baby back faster, since they don't have to try things until something finally works.
Because lets face it, as cool as those old cars are, they can't compete with the edge that technology gives modern cars in nearly every respect.
- Mark
