Tach Pulse (RPM) Signal
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 1997 Pontiac Grand Prix, 1997 Pontiac Grand Am, 1997 Oldsmobile Cutlass Supreme, 1997 Oldsmobile Cutlass, and 1997 Oldsmobile Achieva. However, it is still accessible from the selected car via links, so may be relevant.
Connect scan tool to DLC. RPM should be indicated on scan tool when engine is cranked or running. Tach pulse (RPM reference) will be indicated as a voltage signal when a DVOM (with a minimum 10-megohm input impedance connected to ground) is used to backprobe RPM high reference circuit. For circuit and terminal identification, See the WIRING DIAGRAMS article.