I was told by a dealership that a code should always appear if the IMRC is malfunctioning, but mine hasn't been working for awhile and I've never had a code show up.
Apparently, though, my mechanic pulled a stored(?) code a long time ago from my car, revealing the IMRC malfunction, but a CEL never showed up before he shared that information. So either my car doesn't like to show IMRC related CELs, or other Contours share the same problem.
