Your dealer can determine which EIS is installed by using SDS. The Parts Dept. can then check to see if it's the correct one. The whole thing shouldn't take them more than a half hour.

In the meantime, let the Svc. Mgr. drive the car until he verifies the problem. If they actually see it happen they have no choice but to follow through until the problem is resolved. I'm curious how this will end up. Let us know what happens next.