Dublin Institute of Technology offers students a number of different routes into engineering, allowing many non-standard entrants the opportunity to study the discipline provided they fulfil certain criteria. The final aim of many of these students is to achieve an Honours Degree in Engineering, which takes a minimum of 4 years. Apart from the first year of the course, the other main entry point is at the start of the third year, at which stage students who have performed well in a 3-year Ordinary Degree can begin. However, these students have a wide range of mathematical abilities and prior knowledge, and many are missing the basic skills required for completion of a mathematics module at this level. It is common practice for students to be diagnostically tested upon entry to third level; however, anecdotally, it appeared that many of the mathematical issues uncovered at that point had not been rectified during the students' subsequent studies. In an attempt to quantify the problem, it was decided to pilot an Advanced Mathematics Diagnostic Test that covered many of the key concepts from the early years of Engineering Mathematics. A pass-mark of 90% was set in this assessment. About 167 third-year students studying for an Honours Engineering degree were tested during the pilot study, only two of whom achieved the pass mark on the first sitting. To encourage the other students to revise this crucial material, multiple re-sit opportunities were provided, and a weighting of 10% of the continuous assessment mark for the mathematics module was given to the diagnostic test. Online resources and special classes covering the relevant material were also provided, with the result that 131 of the 167 students reached the necessary threshold by the end of the semester.