According to ETS, as of April 2001 the Engineering GRE Subject Test has been discontinued. The primary reason cited for the decision to cancel administration of the subject test in engineering is the relatively small percentage of engineering students that take the Engineering GRE before going to graduate school. Many graduate schools did not require the Engineering GRE for admissions because they felt it was too general and did not test ones understanding of the specific engineering discipline for which an individual was applying.
If you want to learn more about the old Engineering GRE Subject Test then you can take a look at a few books that were written to help prepare students for the Engineering GRE Subject Test. These books can be quite handy to help students prepare for GRE Subject Tests in related disciplines such as the Physics GRE and Mathematics GRE.
GRE Practicing to Take the Engineering Test 3rd Edition (isbn=0446395773) by ETS
The Best Test Preparation for the GRE Engineering (isbn=0878916016) by REA
GRE Engineering Review (isbn=0961476060) by Merle C. Potter PE PhD