With coast-down off, the car glides in neutral when you take your foot off the accelerator. When cruising on the freeway, it's better to turn coast-down off because it's not efficient to be constantly slowing down, then speeding up.
Upon taking the car in, I was asked to leave it because it turned out that the RSA (run-shift assembly) computer would have to be replaced. The RSA coast-down switch was apparently working fine, but the computer monitoring the switch was not.
So once again, it was an overnight stay for the EV-1, but at least at the same time, Saturn also replaced the broken wheel cover discovered during the previous service visit. Unfortunately this did NOT include the installation of the software upgrade (it's not ready yet) to fix the possible problem with false low tire pressure warnings, so we'll have to check in again at the end of January.
Once again Saturn service seemed to be very competent and efficient in taking care of the problem. I guess, though, that they are not servicing very many EV-1's because there was some confusion over the fact that a key to the car couldn't be found so that it could be returned to me. They forgot that no key is required to unlock the doors or start the car!