Significant savings in workshop man-hours and vehicle downtime can be made through the adoption of electronic diagnostic techniques which have been developed in the last five years. The most recent advances have been made possible a) through availability of suitable computer hardware using compatible software programs, and b) provision of engine (and vehicle) running data from modem diesel fuel system electronics. The workshop engine troubleshooting procedures, followed via selectively sequenced on-screen displays, make the technician's task simpler and more cost effective.